Objective To investigate the etiologic factors of chronic prostatitis following sexually transmitted urethritis. Methods The pathogens have been detected in 86 patients with chronic prostatitis following sexually transmitted urethritis. Results 57 strains (66.3%) of bacteria were cultured in expressed prostatic secretions(EPS) from 86 patients,in which gonococcus was the majority of cultures,accounting for 38.4%. Chlamydia trachomatis (CT), ureaplasma urialyticum (UU) and gonococcus were also detected by polymerase chain reaction (PCR) in expressed prostatic secretions,25.6%(22/86), 22.0%(19/86),and 43.0%(37/86) showed positive results respectively. Conclusions Gonococcus,chlamydia trachomatis and ureaplasma urialyticum were the main pathogens of chronic prostatitis.The results indicate that pathogen examination plays an important role in treatment of chronic prostatitis following sexually transmitted urethritis.