Malacological and epidemiological investigations have been done in Katana Health Zone during the period from 2001 to 2011. The results shown that the schistosomiasis exists and constitutes a problem of health in this region. A total of 189,475 stools examinations and 11,000 of urines done during the ten years passed; 1,904 cases of schistosomiasis due to Schistosoma mansoni have been observed. That is a rate prevalence of 0. 95 % and 39 cases of Schistosoma haematobium have been recorded. That is a rate prevalence of 0.35 %. Methodical treatment per os of infested subjects by Ambilhar and the control of intermediate host by molluscicidal no toxic to human and environment are measures to take immediately.