Two cases of recurrent hepatic injury which appeared in the first trimester of pregnancy were studied. Case 1 was a 35 year old woman, gravida 4, para 0, who suffered repeatedly from hepatic injury requiring induced abortions. The patient was healthy before the pregnancies and the plasma aminotransferases increased after 8 weeks gestation and promptly returned to normal after the abortions. No fluctuation of aminotransferases was observed in the menstrual cycle. A liver biopsy immediately after abortion showed spotty necrosis of hepatocytes with mononuclear cell infiltration. Most of the infiltrating cells were cytotoxic T cells that were directly in contact with hepatocytes. Numerous lymphocytic infiltrations were also found in the decidua of the uterine curettage material. The patient's lymphocytes showed conspicuous blast transformation in culture with human chorionic gonadotropin (hCG). The hCG was detected in close vicinity to the injured hepatocytes by immunostaining. Case 2 was a 23 year old woman, gravida 2, para 0, who underwent an induced abortion due to hepatic dysfunction in the first pregnancy. Although hepatic dysfunction reappeared from 10 weeks gestation during the second pregnancy, her health gradually improved with conservative therapy and resulted in a full-term delivery. She lacked allergies to drugs or foods and was healthy when she was not pregnant. These two cases suggest that some hepatotoxic materials appeared transiently in the first trimester. The results of Case 1 suggest strongly that hCG on the hepatocytes was recognized as an antigen and evoked lymphocytic attack.