Endocervical specimens obtained from 251 registered prostitutes working in a brothel in Izmir, were screened for Chlamydia trachomatis by using a direct fluorescent antibody test. Twenty seven of these specimens were excluded because of inadequate sampling. Of the remaining 224 samples, 57 (25.4%) were found positive for C. trachomatis. It is concluded that, prostitutes play an important role in the transmission of chlamydial and other sexually transmitted diseases, and routine screening and appropriate treatment of chlamydial infections in prostitutes will help to control this disease in the general population.