Our study was designed to establish the necessity of routine evaluation of patients with inflammatory (IIIA) and noninflammatory (IIIB) types of nonbacterial prostatitis (NBP) for chlamydial and ureaplasmal infections. From 1999 to 2001, 165 patients with a mean age of 35 years (range 20-54 years) were evaluated for the syndrome of chronic prostatitis. The evaluation included scoring with Prostate Symptom Score Index (PSSI) and NIH Chronic Prostatitis Symptom Index (CPSI), Meares-Stamey test and culturing of post-massage urine portion (fourth glass). In all cases, polymerase chain reaction (PCR)-testing of the semen was performed to establish the persistence of Chlamydia trachomatis (ChT) and Ureaplasma urealyticum (UU). Based on laboratory findings (four glass test and post-massage urine culture), in 69 (42%) of 165 cases, NBP was diagnosed, which includes 30 patients with type IIIA and 39 with type IIIB of NBP. According to semen PCR tests, in 11 (36.6%) of 30 cases with IIIA type of NBP, chlamydial (six cases), ureaplasmal (four cases) and a mixture of both (one case) infections were described. Among 39 patients with IIIB type of NBP test was positive in 14 cases (36%), where UU was presented in eight and ChT in six cases. In patients with previously diagnosed inflammatory as also noninflammatory NBP, according to four glass test, chlamydial and/or ureaplasmal infections can be presented. Although their role in pathogenesis of prostatitis remains speculative, however, testing for infections is highly recommended.