We reviewed 409 patients who had prostatitis syndromes during the period 1985-1991. Urine analysis, x-ray film of abdomen, and sonograms of the kidneys did not contribute to the diagnosis of prostatitis. In 22 percent of the urine samples, slight-to-moderate atypia was seen in urine cytology but no malignancy was found. Uroflowmetry data were abnormal for 30 percent of the patients, and thus uroflowmetry may contribute to treatment selection of patients who may gain from specific drugs such as the newly developed alpha-1 receptor blocking agents. Positive bacteria cultures were found in 10.4 percent of the prostatic fluid cultures and in 14.3 percent of cultures of the urethra. Ureaplasma urealyticum was seen in 19.6 percent of the prostatic fluid cultures and in 32 percent of cultures of the urethra. Prostatic fluid cultures did not give additional information, and the outcome of semen cultures showed a poor correlation with urethra or prostatic fluid cultures. In this series, the most advocated treatment remains the antibiotic treatment (75% of patients) bringing relief of complaints in 35.6 percent of the patients and cure in 23.8 percent. However, similar results were found if no antibiotics were administered (relief of complaints in 31.6% and cure in 30.5%) and more than one course of antibiotics did not improve these results. Consequently, we advocate the use of specific antibiotics only when the causative bacterial agent has been identified.