1998–99 Országos Bajnokság I (men's water polo) was the 93rd water polo championship in Hungary.
First stage #TeamMWDLG+G−P1.Ferencvárosi TC-Vitalin221831227116392.BVSC-Brendon221813264148373.Honvéd-Spartacus VE221633213144354.Vasas SC-Plaket221534188142335.Újpesti TE-Taxi2000221534233122336.ÚVMK Eger-Egervin229211176193207.Kontavill-Szentesi VK227411147185188.Szolnoki VSC227213168198169.ELTE-BEAC-Intruder2262141292141410.Tabán Trafik-Szegedi VE2242161311811011.OSC222119105231512.MAFC-P&P2212191202274
Championship Playoff Relegation Playoff Relegation Pld - Played; W - Won; L - Lost; PF - Points for; PA - Points against; Diff - Difference; Pts - Points.
Championship Playoff
Final standing
Qualified for the 1999–00 LEN Champions League Qualified for the 1999–00 LEN Cup Winners' Cup Qualified for the 1999–00 LEN Cup relegation play-off Relegation to the 1999–00 OB I/B
RankTeam BVSC-Brendon Ferencvárosi TC-Vitalin Honvéd-Spartacus VE Vasas-Plaket 5 Újpesti TE-Taxi2000 6 ÚVMK Eger-Egervin 7 Kontavill-Szentesi VK 8 Szolnoki VSC 9 ELTE-BEAC-Intruder 10 Tabán Trafik-Szegedi VE 11 OSC 12 MAFC-P&P
1998–99 OB I ChampionsBVSC-Brendon7th Title Gábor Kis, Tamás Märcz, Zoltán SzécsiHead coachGyörgy Gerendás
Play-off Tabán Trafik-Szegedi VE – OSC 10–6, 3–7, 9–8, 4–6, 10–3
ELTE-BEAC-Intruder – Tabán Trafik-Szegedi VE 10–5, 8–4, 9–8
Sources Gyarmati Dezső: Aranykor (Hérodotosz Könyvkiadó és Értékesítő Bt., Budapest, 2002.)