In Toulouse, various epidemiological works and biological results regarding toxoplasma infection permitted us to study immunity in pregnant women. 66 to 70% are immunized. Incidence of acquired toxoplasmosis is 1 to 2 for 1,000 pregnancies. Carefully planned, regionalized programs with obstetricians and pediatricians are realized to prevent congenital toxoplasmosis. Epidemiological studies may be realized to estimate the prevalence and the incidence of congenital toxoplasmosis before such programs can be recommended on a national scale in tropical area.