A cross-sectional study was conducted among displaced pregnant women in Mozambique to determine the prevalence and correlates of HIV infection and syphilis. Between September 1992 and February 1993, 1728 consecutive antenatal attendees of 14 rural clinics in Zambézia were interviewed, examined, and tested for HIV and syphilis antibodies. The seroprevalence of syphilis and HIV were 12.2% and 2.9%, respectively. Reported sexual abuse was frequent (8.4%) but sex for money was uncommon. A positive MHA-TP result was significantly associated with unmarried status, history of past STD, HIV infection, and current genital ulcers, vaginal discharge, or genital warts. Significant correlates of HIV seropositivity included anal intercourse, history of past STD, and syphilis. In summary, displaced pregnant women had a high prevalence of syphilis but a relatively low HIV seroprevalence suggesting recent introduction of HIV infection in this area or slow spread of the epidemic. A syphilis screening and treatment programme is warranted to prevent perinatal transmission and to reduce the incidence of chancres as a cofactor for HIV transmission.