Concerning respectively 93 observations got in the laboratory of "Pathology" of the Institut Pasteur (from 1954 to 1976) and the laboratory of "Pathology" of the Hospital of Befelatanana, Tananarive (from 1960 to 1975) the authors would like to point out to the medical doctors the pseudo-tumoral aspects of the bilharziasis due to Schistosoma mansoni. 1(0) The pseudo-tumoral aspects of the intestinal bilharziasis are relatively seldom complications of this parasitosis. 2(0) The malignant macroscopical aspect of these pseudo-tumors added to an often alarming symptomatology, if not possible association of cancer and bilharziosis, often brings mistakes in diagnosis. 3(0) Therefore and especially in endemic areas, biopsy is required or at least a medical proof treatment, before any surgical act at least with children or young people, in case of malignant pseudo-tumor which is actually but a bilharziasis.