Drug-induced hepatotoxicity covers the clinical and pathological expressions of almost any acute or chronic liver disease. Liver damage is due to intrinsic toxicity of the drug (paracetamol) and/or immunoallergic mechanisms (halothane). Acute injury may be cytotoxic or cholestatic. Cytotoxic injury is characterized by necrosis (paracetamol, halothane) or steatosis (valproate). Cholestatic injury can be associated with immune-mediated portal inflammation (chlorpromazine) or solely attributed to inhibition of transport systems (cyclosporin A). Chronic drug-induced disorders include chronic active hepatitis (methyldopa), autoimmune hepatitis (tienilic acid), alcoholic steatohepatitis-like reactions (amiodarone), indolent fibrosis (methotrexate), chronic cholestatic diseases, vascular lesions, and hepatic neoplasms. The clinical and morphological picture of many drug-induced liver diseases is nonspecific. Diagnosis is based on thorough drug history, temporal relationship, time-course of liver dysfunction, and the exclusion of other causes. Treatment consists of instant withdrawal of the suspected drug and administration of acetylcysteine as early as possible in case of paracetamol intoxication. Drug-induced liver diseases are usually reversible, but prolonged treatment leads to progression and liver cirrhosis.