In order to elucidate some of the epidemiological factors involved in the acquisition of Toxoplasma infections in Norway, 196 women were requested to answer a series of questions in their post-natal periods. Of these women, 27 had recently been infected with T. gondii, 84 had old infections, and 85 were non-infected. The answers given indicated that frequent intake of raw meat and frequent travelling abroad, especially to countries with high infection risks, were of great significance for the contamination among adults. Living in rural districts appeared to represent a predisposing factor for the acquisition at younger ages. Contacts with animals, especially cats, were not shown to increase the infection risk. With special reference to the results obtained, a list of instructions to sero-negative pregnant women is proposed in order to prevent congenital toxoplasmosis in the Scandinavian countries.