Conhecer a soroprevalência gestacional de agentes que possam ser transmitidos da mãe para o feto e causar doença é uma ferramenta essencial para formulação de políticas públicas de saúde, favorecendo o planejamento de ações programáticas de prevenção e assistência. Soroprevalência ABSTRAcTThe seroprevalence of antibodies for HIV, syphilis, toxoplasmosis, cytomegalovirosis and rubella and its association with age and origin was investigated among pregnant women in Sergipe, northeastern Brazil. A total of 9,550 pregnant women (2,112 from the state capital and 7,438 from other municipalities) were enrolled in the study and consecutively tested during their first antenatal care visit in 2007. The following serum prevalences were found: syphilis (0.9%; 95% CI 0.7%-1.6%), HIV (0.14%; 95% CI 0.08%-0.2%), toxoplasmosis (IgG 69.3%; 95% CI 68.3%-70.2%; IgM 0.4%, 95% CI 0.3%-0.6%), cytomegalovirosis (IgG 76.6%, 95% CI 75.7%-77.5%; IgM 0.2%, 95% CI 0.09%-0.3%) and rubella (IgG 71.6%, 95% CI 70.7%-72.6%; IgM 0.1%, 95% CI 0.04%-0.2%). Toxoplasmosis seropositivity increased with age. The prevalences of IgG antibodies for toxoplasmosis, cytomegalovirus and rubella were higher in Aracaju (state capital) than in other municipalities in the State of Sergipe. The results showed that a large proportion of the pregnant women, particularly in municipalities other than the state capital, were susceptible to toxoplasmosis, rubella and cytomegalovirus, with a risk for their infants.