We previously reported that seminal vesiculitis was associated with acute epididymitis, and that Chlamydia trachomatis was the major causative pathogen for infection of the seminal vesicle, suggesting that seminal vesiculitis was a discrete disease entity. In this paper, we report two patients with bacteriologically and cytologically proven seminal vesiculitis who had asymptomatic urethritis but not epididymitis. The clinical courses of these patients suggest that chlamydial seminal vesiculitis may be a cause of asymptomatic infection of the urethra or subsequent development of acute epididymitis.