A total of 45 patients with acute hepatitis were detected in a medical facility of Bangladesh over a period of 6 months. All of them were physicians, nurses, students or employees of the hospital. About 50% of these patients suffered from acute hepatitis within a period of 2 months. All of them had clinical and biochemical evidences of acute hepatitis. All of them shared common working places as well as common dining and cooking facilities. Although the disease was supposed to be caused by hepatitis viruses, none of them were expressing IgM type antibody to hepatitis B core antigen (IgM anti-HBc) or hepatitis C virus (IgM anti-HCV). IgM type antibody to hepatitis A virus (IgM HAV) was detected in one patient and IgM type antibody to hepatitis E virus (anti-HEV IgM) were found in 14 patients. In conclusion, diagnosis of etiological agent of viral acute hepatitis constitutes a formidable challenge to the existing health care delivery system in developing countries as available serological and routine screening fails to find the proper etiological agent.