In malaria endemic areas, pregnancy predisposes previously immune women to clinical and subclinical malaria infection. While parameters of humoral immunity do not seem to be affected by pregnancy, suppression of cellular immunity has been demonstrated for a number of antigens. In this study of women from a rural area of the Gambia where falciparum malaria is holoendemic, we show that lymphoproliferative responses to Plasmodium falciparum antigens are depressed in pregnant women compared to parity matched non-pregnant women, and that this effect is particularly marked in primigravidae. The data also indicate that malaria antigen induced gamma-interferon production may be depressed in pregnant women. There was no significant difference in antimalarial antibody titers between the 2 groups.