The number of patients with autoimmune hepatitis with histological features of acute hepatitis (AIH-AH) has been increasing recently. Here, the clinical features of patients with AIH-AH have been compared with those of patients with AIH with histological findings of chronic hepatitis (AIH-CH) and liver cirrhosis (AIH-LC). The levels of total serum bilirubin (P<0.05) and serum transaminases (P<0.05) were significantly higher in patients with AIH-AH than in patients with AIH-CH and AIH-LC. However, the serum levels of gamma-globulin (P<0.05) and immunoglobulin G (P<0.05) were significantly lower in AIH-AH than in patients with AIH-CH and AIH-LC. The aggregate score according to the criteria of the International Autoimmune Hepatitis Group in 1999 was also significantly lower in AIH-AH patients than in patients with AIH-CH and AIH-LC (P<0.05). Eleven patients with AIH-AH were treated with corticosteroids, however, the clinical response was insignificant in three patients. In summary, it is difficult to diagnose of patients with AIH-AH using the criteria of the International AIH scoring system. We wish that this scoring system would be modified in the near future.