A Commemorative Conference of Pneumocystis Discovery First Centenary was held in Brussels, Belgium, on 5-6 November 2009. A total of 16 keynote speakers from different countries attended the meeting. This conference has allowed the principal European and non-European groups who are working on Pneumocystis infection to gather together, in order to expose the most recent advances accomplished in the basic and translational scientific knowledge of Pneumocystis infection, and to discuss the trends of future research in this area.