Our study was based on 3 cases of visceral leishmaniasis of adults hospitalized at the University Hospital Center of Avicenne during the period 1980 – 1983. Leishmaniasis is relatively rare malady, sporadic and localized. We find it in the northen region of the country. It attacks young male adults. Leishmania donovani infection takes place at the end of the hot season, in rural areas and. when the socio-economical conditions are poor. Besides the three main characteristic symptoms, the clinical pictures include also: cutaneous, pulmonary and digestive involvement. The symptoms present a misleading picture. Hematologic and cytological studies, as well as protide findings oriented the diagnosis. Sterna I puncture findings confirmed the diagnosis, so did the serological tests. Specific therapy based on the use of Glucantime * and Lomedine * administrated according to the classical method gave satisfactory results, except in the case where the malady was undetected for a long time and, where the toxicity of the medication could not be tolerated. Finally, prophylaxis against leishmaniasis is necessary and it consists of disrupting the parasite’s life cycle