Sexually transmitted infections (STIs) represent a public health problem worldwide. The aim of this study was to investigate the prevalence of curable STIs caused by Neisseria gonorrhoeae, Chlamydia trachomatis and Ureaplasma urealyticum in female sex workers in a population from Zulia State, Venezuela. Seventy eight (78) women attended a health monitoring sanitary controls were evaluated, and PCR amplification assays were used to detect the three microorganisms in endocervical samples. In 33.3% of the samples, at least one microorganism was detected: U. urealyticum was found more frequently (25.6%), followed by N. gonorrhoeae (18%), and C. trachomatis (12.8%). A significant association between N. gonorrhoeae and C. trachomatis was found (p