In utero infection with Toxoplasma gondii may result in congenital defects such as hydrocephalus, chorioretinitis and mental retardation; these defects may be present at birth or may develop later in life. Prevention of this disease can be achieved in different ways. The most effective measure is to prevent the acquisition of the disease during pregnancy by avoiding risk factors for Toxoplasma gondii infection. Health education may decrease the incidence of toxoplasmosis during pregnancy by 60%. A second preventive measure is based on serologic screening during pregnancy to identify infected women. Treatment during pregnancy results in a significant reduction in the incidence of sequelae including severe handicaps. A third possible intervention is treating infected neonates. Antibiotic treatment of infected children has a beneficial effect on the development of sequelae and the sooner therapy is started after birth, the better the outcome. This overview presents the potential benefits and harms of these different options available for the prevention of congenital toxoplasmosis.