Sixty four men with urethritis were studied in a Sexually Transmitted Diseases Center in Medellin; 85.90/0 were diagnosed as gonorrhea; this finding differs from previous ones from the same city that showed non-gonococcal urethritis to be predominant; the difference may be due to socio-economic factors, that need further study, or to the fact that in the present series patients had not received any antibiotic during the previous six months; if the latter possibility were true many cases of NGU of the former series could in fact have been post-gonococcal urethritis (PGU).