After 20 years, some anesthesiologists still doubt that halothane hepatitis is a genuine problem, while others, accepting the fact, would attribute the response to altered sensitivity. We report here a clear-cut instance of severe hepatitis following repeated anesthesias with halothane in an obese woman who also had slight hepatic dysfunction following thiopental-nitrous oxide—fentanyl anesthesia. Tests for HBS(hepatitis B surface) antigen and altered sensitivity to all of the anesthetics given were all negative, while biopsy of the liver revealed no evidence of chronic hepatitis.