The incidence of hepatic adverse drug reactions (ADRs) remains unknown in the general population. The goal of this population-based study was to assess the incidence and seriousness of hepatic ADRs. All new cases of symptomatic drug-induced hepatic injuries were collected by 139 trained physicians (general practitioners [GPs] and specialists) between November 1997 and November 2000 in an area containing 81,301 inhabitants who could not go elsewhere for medical care. Over 3 years, 34 cases of hepatic ADRs were collected, 82% of them in outpatients. Global crude annual incidence rate was 13.9 +/- 2.4 per 100,000 inhabitants; corresponding standardized annual global rate was 8.1 +/- 1.5. There was no difference between urban and rural areas. Standardized incidence female/male ratio was 0.86 (0.26-2.90) until 49 years of age and 2.62 (1.00-6.92) after this age. Diagnosis was carried out by GPs in half of the cases. The outcome was recovery for 32 patients and death for 2. The main drugs implicated were anti-infectious, psychotropic, hypolipidemic agents, and nonsteroidal anti-inflammatory drugs (NSAIDs). Our results suggest that the number of hepatic ADRs in the French population would be 16 times greater than the number noted by spontaneous reporting to French regulatory authorities. In conclusion, the incidence and seriousness of drug-induced hepatitis are largely underestimated in the general population. These results may be useful for further evaluation of drug-induced hepatotoxicity.