The use of an official drug adverse reaction assessment procedure became compulsory in France in 1984. The method proposes various qualifications for chronologic and semiologic criteria but does not define them. Consensus meetings have been organized in order to define, in the main pathologic fields, the adverse reactions themselves and the various qualifications of the criteria. This paper reports the results of meetings attended by hepatologists from university hospitals, members of the National Network of pharmacovigilance and representatives of Roussel Uclaf Drug Monitoring Department for drug-induced acute hepatitis. Participants studied (a) the limits of the time interval between the appearance of the adverse reaction and the beginning or the end of the treatment with the suspected drug; (b) the interpretation of the course of disease with or without cessation of treatment; (c) the interpretation of a possible rechallenge; (d) the signs evoking a drug-induced origin and the risk factors, as well as the investigations to be performed in order to eliminate other possible causes.