PDE may refer to:
Mathematics Partial differential equation, differential equation involving partial derivatives (of a function of multiple variables)
Life sciences Phosphodiesterase, enzyme important in intracellular communication Pug dog encephalitis
Organizations The European Democratic Party (esp. in Spanish, French or Italian languages) The Pennsylvania Department of Education
Technology and engineering Program development environment Pulse detonation engine, proposed substitute to the traditional jet engine
Philosophy Principle of double effect
Places Punta del Este
Other modes of abbreviation Polydichloric euthimal, fictional substance Pde (or Pde.), "Parade" (when serving as part of the proper name of a street or other way) Present Day English Preliminary Determination of Epicenters, the final earthquake bulletin of the National Earthquake Information Center (NEIC)