The aim of this study was to confirm the clinical efficacy of a single-dose azithromycin (AZM) regimen (1000 mg) for patients with nongonococcal urethritis in real-life practice. The study finally evaluated 55 patients, 42 who were symptomatic and 13 who were asymptomatic, after excluding 40 who visited clinics only once. Sixteen of the symptomatic patients were diagnosed as having nongonococcal chlamydial urethritis, 7 as having nongonococcal nonchlamydial urethritis, and 19 as having urethritis without any microbial detection. Chlamydia trachomatis was detected in 11 asymptomatic patients, Mycoplasma genitalium in 1, and Ureaplasma urealyticum in 1. Of the patients who were microbiologically evaluated before and after single-dose AZM, microbiological cure was achieved in 87% (20/23) of those with symptomatic nongonococcal urethritis and in 100% (13/13) of those with asymptomatic nongonococcal urethritis. The clinical cure rate was 86% for the 42 symptomatic patients with detectable and undetectable pathogens. There were adverse events in 5 (9%) patients but they were commonly mild and self-limited. In conclusion, the single-dose AZM regimen was well tolerated and eradicated the estimated and potential pathogens of nongonococcal urethritis.