Amoxicillin-clavulanate potassium, a semisynthetic penicillin-beta-lactamase inhibitor combination drug, is a widely used oral antibiotic. Since the marketing of this drug in 1984, more than nine million prescriptions have been dispensed. Several cases of jaundice and hepatic dysfunction have been observed and reported to the Food and Drug Administration and the pharmaceutical company (Beecham Laboratories). A review of 18 of these cases revealed a predominantly cholestatic syndrome in 7 cases, a mixed hepatocellular-cholestatic picture in 6 cases, a hepatocellular pattern in 4, and in 1 case the injury could not be clearly defined. No fatalities were observed, and all cases had reversal of hepatic dysfunction upon cessation of the drug. Fever was present in 2 patients and eosinophilia in 6 of 10 patients tested, suggesting a hypersensitivity phenomenon contributing to hepatic dysfunction in some of the cases. A percutaneous liver biopsy had been performed in 7 of 18 patients and four of these were reviewed by the authors. Prominent centrizonal cholestasis was seen in all four biopsies. Additionally, 1 patient had periportal and another had midzonal cholestasis. Although infrequent, recognition of an often benign cholestatic syndrome associated with amoxicillin-clavulanate potassium will help avoid unnecessary, invasive, and expensive diagnostic studies and also ameliorate symptoms upon withdrawal of the drug.