A case of tolazamide-induced hepatic injury is reported. Injury was documented by abnormal liver tests, including an elevated alkaline phosphatase, 5' nucleotidase and serum glutamic oxaloacetic transaminase. Liver biopsy confirmed the degree and type of injury which consisted of severe portal inflammation, bile duct proliferation and early fibrosis. The case is reported to further establish tolazamide as a drug capable of producing hepatic injury and to report a new form of hepatic injury attributable to a sulfonylurea agent.