Malignancies may cause cholestatic jaundice through well-recognized mechanisms (e.g., bile duct obstruction or widespread hepatic infiltration). Paraneoplastic syndromes associated with malignancy, particularly with renal cell carcinoma (Stauffer's syndrome) and malignant lymphoproliferative diseases, can induce a reversible form of cholestasis through an unclear pathogenetic mechanism. Prostate cancer presenting initially with cholestatic jaundice without any obvious cause (i.e., obstruction or infiltration) has been reported in 2 cases in the medical literature. We report a patient who presented with pruritus and cholestatic jaundice. During the diagnostic work-up, prostate cancer was diagnosed. Conjugated bilirubin and alkaline phosphatase levels were increased markedly with modest increases of gamma-glutamyltranspeptidase and transaminase levels. The results of appropriate investigations performed during the patient's hospitalizations indicated no evidence of hepatic metastases or extrahepatic biliary obstruction. After treatment with flutamide and leuprolide, the patient's symptoms and the laboratory abnormalities reversed rapidly. We regard the cholestatic jaundice of this patient as part of a paraneoplastic syndrome; the cause of cholestasis remains an enigma. Patients with unexplained cholestasis should be investigated for malignancies, including prostate cancer.