OBJECTIVE: To assess the seroprevalence of immunity to the rubella virus in pregnant women in Haiti attending the Obstetrics and Gynecology Department of the State University Hospital, in the capital city of Port-au-Prince, in order to help with the introduction of the rubella vaccine for the population and provide protection for women of reproductive age in the country. METHODS: This cross-sectional study was done between February 2002 and May 2002. A total of 503 pregnant women were tested for rubella-specific immunoglobulin G antibodies, using enzyme immunoassay; 8 of those women were later excluded because they did not know their age, leaving 495 women in the analysis. RESULTS: Of the 495 participants included in our analysis, 471 of them (95.2%) were seropositive; only 24 of them (4.8%) were seronegative (susceptible). A statistically significant difference (P = 0.02) was found in the rate of seronegativity for rubella virus between the pregnant women living in the Port-au-Prince area (17 of 426 women, or 4.0%) and those living in rural areas (7 of 69 women, or 10.1%). In terms of age, 81 of the 495 (16.4%) women were under 21 years old. CONCLUSIONS: This study is an important first step in addressing the issue of prevalence of rubella virus infection among Haitian women and in dealing with the still-underrecognized public health problem of congenital rubella syndrome in Haiti. We recommend additional research that uses randomized sampling and includes a significant proportion of women from rural areas of the country.