We report a case of acute hepatitis in a 28-year-old male with acquired rubella infection. Serological tests revealed acute rubella virus infection and ruled out infection by other common viruses, including type A and type B hepatitis viruses. The patient showed not only marked increase of lactate dehydrogenase (LDH) activity, with only slight liver dysfunction, but also platelet and kidney injury, suggesting systemic rubella virus infection. Because the liver dysfunction was slight, liver biopsy was not performed. When a patient has mild, transient hepatitis accompanied by high LDH activity in comparison with both aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, we should take a common viral infection such as rubella into consideration when making a diagnosis.