Fifty-seven adult patients with acute hepatitis and 34 comparison patients without liver disease were evaluated using a newly developed Western blot assay for IgM antibody to hepatitis E virus. The mean age of patients with hepatitis was 32 years (range, 18-55 years); 88% were male. Among patients with acute hepatitis, hepatitis A (anti-HAV IgM positive) was diagnosed in two (4%), hepatitis B (anti-HBc IgM positive) in three (5%), and hepatitis E (anti-HEV IgM positive) in 34 (60%). One hepatitis patient had CMV IgM, another had EBV IgM, and 16 others (28%) were negative for all serologic markers of acute viral hepatitis. No patient with acute hepatitis A or B and none of the comparison patients without acute hepatitis had anti-HEV IgM. All but one case of acute hepatitis E were found among expatriates of Asian origin, and acute hepatitis E was associated significantly with recent travel to the Indian subcontinent. These data suggest that acute hepatitis E is common among foreign workers in Kuwait but that little HEV transmission is occurring directly in Kuwait.