In Morocco, the seroprevalence of toxoplasmosis in pregnant women living in Rabat, was estimated by analyzing antibodies (IgG, IgM) levels using an ELISA test. The analysis of 2456 serums at the Institut National d'Hygiène showed that the seroprevalence of toxoplasmosis is about 50.6%. According to the questionnaire, the lack of knowledge about this disease and soil contact could be the main causes of toxoplasmosis infection. The use of IgG avidity test has excluded a recent infection in 93.5% of pregnant women with IgM positive sera.