The 2002–03 season was FC Basel's 110th season of competition, and the club's 9th consecutive season in the Nationalliga A, the top flight of Swiss football. Basel played their home games in the newly constructed St. Jakob-Park complex. René C. Jäggi, who had been the club chairman for the previous six seasons, stood down at the AGM in October, and businessman Werner Edelmann was elected as the new chairman.

The club sought to retain the Swiss Nationalliga A and Swiss Cup titles after winning the double the previous season. They also sought to compete in the Champions League for as long as possible, as well as reach its group stage.

Basel ended the domestic league season as runners-up in the league and winners of the Swiss Cup. They also reached the second group stage of the Champions League.

Overview Off-season and pre-season Basel started the season with high aspirations as reigning champions and cup holders. Basel and Grasshopper Club Zürich were the favourites to win the domestic championship title. Basel chose winning the championship as their top goal. Their second objective was to defend the Swiss Cup because it would be played at their home stadium, St. Jakob-Park. Basel also entered the 2002–03 Champions League in the second qualifying round and aimed to reach the group stage.

Massimo Ceccaroni retired from his professional career prior to the season. Ceccaroni is still considered to be a cult figure in Basel, due to his 25 years total of loyalty towards the club and the fact that he never scored a goal in the top flight of Swiss football. As a result of making very few appearances for the team the previous season, the club decided not to renew his contract at the end of the season, and his professional career came to an end. Ceccaroni played a total of 605 games for Basel from 1987 to 2002. 398 of these games were in the Nationalliga A and Nationalliga B, 34 in the Swiss Cup, 20 in the European competitions (UEFA cup and UIC) and 153 were friendly games. He scored six goals throughout his career, four in the Nationalliga B and two during friendlies. Other players who left the squad included fellow retirees Oliver Kreuzer and Romain Crevoisier, and Miroslav König, who transferred to Zürich.

Soon after the season began, Philippe Cravero moved to Servette, first on loan and then definitively. During his tenure of just over four seasons with the club between 1998 and 2002, Cravero played 185 games for Basel, scoring a total of five goals. 108 of these games were in the Nationalliga A, 8 in the Swiss Cup, 16 in the European competitions (UEFA cup and UIC) and 53 were friendly games. He scored two goals in the domestic league and three in friendly matches.

Christian Gross was the first team trainer for the fourth successive season. Knowing the high aspirations for the season, Gross strengthened the team. Alessandro Iandoli advanced to the first team from the U-21 team. Basel's biggest pre-season signings were Bernt Haas, who was loaned in from West Bromwich Albion, Julio Hernán Rossi transferred in from Lugano, goalkeeper Eric Rapo came in from and Antonio Esposito from St. Étienne.

Six pre-season test games were planned for June and one for early July. The Nationalliga A season began on 6 July 2002 with an away game against Aarau, and the Champions League qualifying started on 31 July with an away tie against Žilina. In the Swiss Cup, all the league teams had a bye and qualified for the round of 32, which was to take place on 22 February 2003.

Winter break During January 2003, George Koumantarakis left the club and transferred to English team Preston North End, who at that time played in the English Championship.

Campaign Friendly games Basel started the season off with various warm-up matches. Their opponents included teams from the Swiss lower league, a team from Brazil, and PSV Eindhoven of the Netherlands. During the summer, Basel visited a training camp in America and played three matches against teams from the USL Premier Development League and Major League Soccer. Basel entered the Sempione Cup, which was played in Balsthal. The club won the first match against Austrian team SK Rapid Wien 3–0 and the second against Slovakian team Inter Bratislava 2–0. Basel were placed second in the final classification.

Domestic league Qualifying round The Swiss Football Association (ASF-SFV) were changing the format of the domestic league during the season. Since the 1987–88 Nationalliga A season there had been 24 teams in the Nationalliga, 12 in the Nationalliga A and 12 in the Nationalliga B. In the first stage, there was a qualifying phase played as a double round-robin tournament. Three points were given for a victory and one for a draw. In the second phase, the top eight clubs played a further double round-robin for the championship; each team took half of the points and rounded up to complete units from the qualification round into the second stage as bonus. The last eight teams played against relegation to the amateur league and the last four teams from the top-level played a promotion/relegation round for the top tier in the following season. This was to be the last season in this format. The new format would reduce the number of clubs to 20, with ten teams in the top tier and ten in the second tier. Therefore, this year there was an additional relegation.

The season started well for Basel and they were undefeated in their first seven matches, winning five and drawing two. FCB lost the two following games and slipped seven points behind the Grasshoppers who in the same period had won eight of their nine games. Despite defeating GC on match day 10 in their own Hardturm stadium the following weekend, the rivals remained clear in the ranking. Gross regrouped his team and they won nine and drew two of the following eleven games, catching and overtaking their rivals in the table. A 1–2 home defeat against GC on match day 21 cost FCB the lead. Grasshoppers ended the league qualifying stage as table leaders at the winter break with 49 points, two points clear.

Championship round In the championship playoff round Basel only lost two away games, winning 10 of 14 games. Despite this, because both direct ties against the Grasshoppers were drawn, the Zurich-based club managed to snatch the title by a single point at the end of the season. The Grasshoppers remained undefeated in the championship group and ended the season with 57 points. Basel were second with 56, 21 points ahead of third placed Xamax. As champions, GC qualified for the 2003–04 Champions League third qualifying round. As runners-up, Basel qualified for the UEFA Cup first round.

In the home match in St. Jakob-Park on 19 April 2003, Hakan Yakin had a good game and scored a perfect hat-trick during the first half of the game as Basel won 3–0 against Young Boys. Yakin showed his other side in the return match in the Stadion Neufeld in Bern one week later. As Young Boys went a goal up, Yakin lost his temper and kicked the ball away, thus collecting a yellow card. Just ten minutes later he committed a rough foul, collecting a second yellow card. By rule, a player that receives two yellow cards in one game is issued a red card and ejected for the remainder of the match, so Yakin was dismissed.

Domestic cup As cup holders the club's aim was to defend the trophy, or at minimum to reach the final, because the final would be played in their home stadium St. Jakob-Park. In the cup, all the league teams had a bye for the early rounds and started in the fifth round, which was scheduled for February. Here they were seeded and could not play against each other. In a match, the home advantage was granted to the team from the lower league, if applicable. Basel were drawn against lower league Yverdon-Sport.

Yverdon-Sport (22 February 2003) The match was held at Stade Municipal in Yverdon-les-Bains and had an attendance of 2,800 fans. After a foul from Gil Bala on Hervé Tum inside the area, Mario Cantaluppi converted the subsequent spot-kick in the 16th minute. Basel controlled the game and could have gone further ahead in the 29th minute, but Julio Hernán Rossi's shot rebounded from the post. In the fortieth minute, Cantaluppi scored his second goal. Following the goal celebrations Rossi was shown a red card for unsportsmanlike behavior. Despite having one man less on the field, Basel dominated the second period and Carlos Varela had a shot against the cross bar. One minute before time Timothée Atouba scored following a set piece to make the final score 3–0 for the visitors.

Servette (4 March 2003) In the round of 16, Basel was drawn against Servette and played at home in the St. Jakob-Park with an attendance of 10,721 spectators. The match was played on level terms and possession was even for the first half-hour. Basel then increased the tempo and pushed the visitors back, creating two good chances, but Christian Giménez failed with both opportunities. Following a corner-kick Basel was awarded a penalty, which was converted by Mario Cantaluppi in the 35th minute. After the break, FCB pushed forward with Giménez and Julio Hernán Rossi often outrunning the defense. After one such move in the 51st minute, Scott Chipperfield was played into position, and his left footed shot gave the team a two-goal lead. Following this, Basel controlled the game, occasionally using their speed, but content to control the ball and the play. The match ended with a 2–0 win for the home team.

Young Boys (26 March 2003) In the quarter-finals, FCB were drawn away against Young Boys. The match took place in the sold out Stadion Neufeld in Bern in front of 10,700 spectators. Despite two early goals from Christian Giménez in the 2nd and 28th minute, YB picked up and turned the game and took the lead. Gürkan Sermeter scored his first goal in the 38th minute, and his second in the 42nd. To make things worse for Basel, Varela picked up two yellow cards during the first half and was dismissed. The score was level as the teams went into the interval, but YB had a one-man advantage. After the break, YB continued their forward pressing and Sermeter completed his hattrick in the 55th minute. Basel then created two good chances. The first went wide of Paolo Collaviti's goal and the second, a header from Murat Yakin, was pushed against the cross bar by Collaviti, but Hervé Tum was in place to sink the rebound from close range. The score remained level at 3–3 at the end of regular time. Hakan Yakin scored the deciding goal and Basel won 4–3 after extra time.

Schaffhausen (15 April 2003) Basel were drawn against lower-league club Schaffhausen in the semi-final. Again, FCB were able to play at home in St. Jakob-Park, which had an attendance of 26,960 spectators. Basel dominated the play from early in the game and the Schaffhausen defence had problems. In the 5th minute Mario Cantaluppi's shot rebounded from the post. In the 7th minute, Julio Hernán Rossi scored, but the goal was disallowed due to a player in an offside position. The Schaffhausen defenders Leu and Fehr were both shown yellow card within the first 23 minutes. In the 26th minute, Antonio Esposito put the home team one goal up. Basel continued to dominate the game but were content to control the ball and play and not to endanger their defense. Yet as the second period ticked away, it became evident that the FCB players were becoming frustrated because they could not add another goal. Scott Chipperfield and Esposito were both shown yellow cards because of this. Jean-Michel Tchouga netted in the 70th minute, but the goal was disallowed due to reckless play. Eventually the team got their second goal in the 90th minute, with Hervé Tum slotting the ball home from the edge of the area. Two minutes later, Esposito netted his second goal and the team's third. Basel advanced as Schaffhausen were defeated.

Neuchâtel Xamax (11 May 2003)