A hospital-based study of acute hepatitis was conducted in Damascus, Syria, from 1995 to 1998. One hundred ninety-three sera from defined acute hepatitis cases were screened by ELISA for IgM anti-HAV, HBsAg, IgM anti-HBc and anti-HCV. Serum samples negative for all markers indicating recent infection by hepatitis A, B, or C were tested for HEV markers. Overall, 47 cases (24.4%) had no detectable hepatitis markers (non-A-E). HAV infection was detected in 71.2% of all viral hepatitis cases. Acute hepatitis B and C constituted 24 and 1.4% of the cases, respectively. Only five cases of acute hepatitis E were noted. Of 47 patients who had non-A-E hepatitis, fifteen (31.9%) tested positive for IgG anti HEV. This study provides indirect evidence that HEV is very likely to be endemic in Damascus, Syria. It reports for the first time the occurrence of hepatitis E in the country, a health problem that should be investigated further.