Israel is endemic for hepatitis E virus (HEV), the causative agent of enteric non-A, non-B hepatitis. Transmission is via the feco-oral route but the possibility of transmission through blood transfusion has been raised. This question was addressed by examining sera from 188 hemophilic patients in Israel. screening was performed with an enzyme immunoassay (EIA) for antibody against hepatitis E virus (anti-HEV) and confirmed with a neutralization test. Sixteen patients (9%) were seropositive for anti-HEV. A statistically significant difference was not found between the seroprevalence in this group and that of a healthy Israeli control population, matched for sex and age. The anti-HEV-seropositive hemophiliacs had the same seroprevalence of antibodies to hepatitis B and C virus and to HIV and the same number of cases with chronic hepatitis as among the anti-HEV-seronegative patients. The seroprevalence of antibodies to hepatitis A virus (anti-HAV) was, on the other hand, higher in the anti-HEV-seropositive group. This study indicates that HEV is not transmitted by cryopre-cipitate or lyophilized factor concentrates. High prevalence of coinfection with hepatitis A supports our conclusion that HEV infection in Israeli hemophiliacs was due mainly to feco-oral transmission. © 1995 Wiley-Liss, Inc.