One of the main concerns of blood transfusion centers is viral hepatitis as a direct result of blood transfusion. Ninety-five percent of these cases are non-A, non-B hepatitis. In order to prevent this disease, blood collections were screened for antibody anti-HBc as well as the level of activity of the alanine aminotransferase in 3,051 blood donors in Guadeloupe. this revealed a particular epidemiological situation, which caused this French country to be rated among moderate endemic zones for hepatitis B virus. As a result of this new screening procedure, 25 percent of the blood collected had to be discarded and was classified with prevalence rates of 21.8 percent HBc antibody, 2.9 percent HBs antigen, and 2.6 percent alanine aminotransferase (45 IU/l). Differences were noted according to sex, age, social-economical level and geographical origin of the blood donors. These data raised many significant questions regarding the vertical transmission of hepatitis B virus, the epidemiological situation of hepatitis B virus in the Guadeloupe population as well as in the rest of the French West-Indies, and also the type of action which must be taken against non-A, non-B hepatitis in a moderate endemic zone for HBV.