A 52-year old woman was submitted to mitral valve replacement. The operation proceeded without complications. Jaundice had been noted since the first postoperative (po) day and increased progressively due to conjugated bilirubin. Abdominal examination was normal and no signs of infection or circulatory failure were noted. Conjugated bilirubin levels increased from 6 mg/dl on the second po day to 20.4 mg/dl on the sixth po day and to 32 mg/dl on the tenth po day. Gammaglutamyl transferase levels were 600 U/L (normal up to 18 U/L) and lactate dehydrogenase levels were 396 U/L (normal) up to 240 U/L) on the seventh po day. Alkaline phosphatase levels were 1880 U/L (normal up to 170 U/L) whereas glutamic oxalacetic transaminase levels were 60 U/L (normal up to 15 U/L) and glutamic pyruvic transaminase levels were 66 U/L (normal up to 17 U/L) on the tenth po day. Abdominal ultrasonography did not disclose dilatation of intra and extra-hepatic biliary system. The patient died after a percutaneous hepatic biopsy procedure. The jaundice was attributed to a cholestatic syndrome after cardiac surgery and cardiopulmonary bypass, due to an impairment of the excretory function of the hepatocyte.