Three hundred and seven patients, 130 children and 207 adults, from a hyperendemic village, underwent an ultrasonography of bladder and kidneys. Prevalence of bladder lesions is 79.3% in children and 61.9% in adults, prevalence of hydronephrosis is 36.1% in children and 9.7% in adults. These study confirms the importance of urologic lesions from schistosomiasis in the irrigation schemes of the Niger river. There is no relationship between frequency and importance of lesions and urinary egg count.