In endemic areas of hepatitis B and C, hemodialysis patients are highly exposed to these infections. So the authors studied the prevalence of hepatitis B and C viruses among chronic hemodialysis patients of CHU A. Le Dantec of Dakar in a cross study carried out from June 1996 to June 1997, in order to identify risk factors and suggest appropriate prophylaxis. The study concerned fifteen chronic hemodialysis patients in an unit of hemodialysis in Dakar. For each patient, clinical and biochemical data were collected serological markers of B and C viruses were tested and HCV-RNA in case of seropositivity to C virus. The mean age of patients were 48 years and average duration of hemodialysis was 40 months. Hepatic injury was silent in all cases. Only one patient (6.7%) was AgHBs carrier while 9 patients (60%) were positive for antibodies anti HBs without previous hepatitis B vaccine. Twelve patients (80%) were found to be HCV-antibody positive and half of them were HCV. RNA positive. Average value of alanine amino transferase was higher in HCV-viremic patients than in seropositive but non viremic patients, although normal. Genotype 2 ac was found in 3 HCV viremic patients but it could not be determined in 3 other patients. Hemodialysis duration and number of blood transfusions were found to be risk factors of HCV infection. The high prevalence of HCV seropositivity among chronic hemodialysis patients in Dakar has led to strengthen precautions in our hemodialysis unit. HCV serological screening in blood donors is advocated.