The objectives of this study were to determine the seroprevalence and risk factors for Human Immunodeficiency Virus (HIV) infection among the antenatal clinic population at the University Hospital of the West Indies (UHWI). Pregnant mothers (4186) attending antenatal clinic at the UHWI were screened for HIV infection between September, 1998, and October, 2000. Tests were performed with the use of Abbott enzyme immunoassay (EIA) kits for the detection of antibodies to HIV 1 and 2. Demographic characteristics and risk factor assessments were performed using a questionnaire for all positive cases and four randomly selected negative controls matched by age to each positive case. Twenty-one women were found to be HIV positive. Nineteen of these women were not previously aware that they were HIV-positive. The seroprevalence of HIV infection among antenatal mothers was 0.5%. The mean age of cases was 29.3 +/- 4.6 years. There was no significant difference between cases and controls with regards to parity, socio-economic status and educational achievement. Women residing in urban Kingston and St Andrew (Odds ratio (OR) 5, 95% confidence interval (CI) 1.4, 18), as well as those with a higher number of lifetime sexual partners (OR 1.42, 95% CI 1.13, 1.79) and those with previous sexually transmitted diseases (OR 3.4, 95% CI 1.1, 10.6) were at greater risk for HIV infection. In contrast, women who commenced coitus at a later age were at less risk of becoming infected (OR 0.79, 95% CI 0.6, 0.97). This study demonstrates a low seroprevalence of HIV in the UHWI antenatal population compared to the reported seroprevalence of 2%-8% in pregnant women in Latin America and the Caribbean. The results from this study emphasize the continuing need for voluntary HIV testing and HIV/AIDS educational campaign for this vulnerable group.