Hepatitis E virus (HEV) is prevalent in Asia and Africa. Recently, it was also described in Mexico, but epidemiologic data from other Latin American countries are scarce. The seroprevalence of anti-HEV in a referral hepatology unit in northern Brazil was determined by testing for anti-HEV IgG in 701 serum samples from our serum bank. Specimens analyzed were from 200 blood donors, 79 patients with acute viral hepatitis (AVH), 392 hemodialyzed patients, and 30 carriers of schistosomiasis. Duplicate test results for anti-HEV were positive in four (2%) of 200 of the blood donors, three (10%) of the 30 carriers of schistosomiasis, and in none of the 392 hemodialyzed patients. Fourteen (17.7%) of the AVH patients were positive, as were six (25%) of 24 with hepatitis A virus, three (11%) of 26 with hepatitis B virus, 0 (0%) of 12 with hepatitis C virus, and five (29%) of 17 with non-A, non-B, non-C hepatitis viruses. Among AVH cases, those with hepatitis A virus had a higher frequency of anti-HEV positivity compared with all other hepatotropic viruses (P < 0.0003). We conclude that HEV is prevalent in northern Brazil. The higher prevalence in patients compared with blood donors could be explained by the lower social condition of patients who sought public health service in this area, in contrast with the heterogeneous socioeconomic distribution of blood donors. Patients with AVH due to hepatitis A had a greater frequency of anti-HEV, probably because of similar routes of transmission for both hepatitis A and E viruses. Finally, the absence of anti-HEV in the hemodialyzed group could be explained by a lower immunologic response found in patients with chronic renal failure.