In order to determine the incidence and the etiology of the sexually trasnmitted diseaes (STD) 500 women, belonging to a high risk group (prostitutes), were studied from August, 1989 to Octuber 1990, and bacteriological and mycological studied were performed. Also, a questionnaire comprising detailed sexual behavior were rendered. High incidence of Gardnerella vaginalis (41.4 percent), Neisseria gonorrhoeae (12.2 percent), Trichomonas vaginalis (10.2 percent) and Candida albicans (10 percent) were found, in contrast with the low level found for Lactobacillus sp. The questinnaire revealed very low utilization of contraceptives as well as condom employement