Urethritis in men has been categorized historically as gonococcal or nongonococcal (NGU). The major pathogens causing NGU are Chlamydia trachomatis and Ureaplasma urealyticum. Trichomonas vaginalis may be involved occasionally. In up to one-half of cases, an etiologic organism may not be identified. In this review we present recent advances in the diagnosis and management of NGU and discuss how they may be applied in a variety of clinical settings, including specialized STD clinics and primary health care practices. In particular, the development of the noninvasive urine-based nucleic acid amplification tests may warrant rethinking of the traditional classification of urethritis as gonococcal urethritis or NGU. Diagnostic for Chlamydia are strongly recommended because etiologic diagnosis of chlamydial urethritis may have important public health implications, such as the need for partner referral and reporting. A single 1-g dose of azithromycin was found to be therapeutically equivalent to the tetracyclines and may offer the advantage of better compliance.