The aim of this investigation was to determine the time of toxoplasma infection more precisely by using an indirect fluorescent antibody test and indirect hemagglutination test in 51 pregnant women whose Sabin-Feldman test and immunosorbent agglutination assay were positive. Analysis of the results of sera tested with the two additional serological assays showed that the infection was acquired during pregnancy in 19 cases, while the other pregnant women had become infected before conception.