Aim:Trichomonas vaginalis may cause symptomatic or asymptomatic urethritis in men. There are few recent studies on the prevalence of T. vaginalis infection in Japanese men, and quantification of the number of cases of urethritis attributable to this pathogen has not been performed in Japan. The aim of this study was to determine the prevalence and morbidity of T. vaginalis infection in Japanese men. Methods: One hundred subjects with or without urethritis were examined for the presence of urethral T. vaginalis using culture swabs. Results: Urethral swabs from all subjects were negative for T. vaginalis. Conclusion:These results indicate Japanese men, including those with urethritis, have a low incidence of urethral T. vaginalis infection or colonization. T. vaginalis appears to be an uncommon pathogen for male urethritis in Japan.