PURPOSE: Prostate specific antigen(PSA) is present in a 10(6)-fold higher concentration in semen than in plasma, but serum PSA is elevated during inflammatory conditions such as chronic prostatitis. We evaluated the seminal PSA and its effect on sperm motility in inflammatory chronic nonbacterial prostatitis/chronic pelvic pain syndrome(CPPS). MATERIALS AND METHODS: Twenty-three patients with inflammatory CPPS(group P) and 11 normal controls(group NL) were enrolled in this study. The semen analysis was performed with a computerized analyzer, and seminal PSA was measured twice using a ELSA-PSA2 radioimmunometric kit(Cis Biointernational). We compared the result in groups P and NL. The subjects were then re-sorted into two groups according to the seminal PSA concentration, with 3.0 mg/ml as the cutoff value, and sperm motility was compared for the high- and low-PSA groups. Statistical significance was measured using the unpaired t-test. RESULTS: The average concentrations of seminal PSA in groups P and NL were 3.67 mg/ml and 1.79 mg/ml, respectively(p=0.048). Sperm motility was not different in the two groups. However, motility(straight-line velocity and average path velocity) was lower in the patients with high seminal PSA(p<0.05). CONCLUSIONS: Inflammatory chronic non-bacterial prostatitis increases the seminal secretion of PSA, and high seminal PSA is correlated with decreased sperm motility.