Drug-induced acute hepatitis may be followed by prolonged cholestasis despite the withdrawal of the drug. Eight patients suffering from prolonged cholestasis caused by several drugs were investigated with sequential liver biopsies. At the early stage, lesions of acute cholangitis were observed in most patients; at the chronic phase, ductopenia, defined by the absence of interlobular bile ducts in at least 50% of small portal tracts, was demonstrated in all patients. Ductopenia might be the consequence of acute cholangitis; the degree of ductopenia and the chronicity of the disease might be directly related to the severity of the early acute damage of bile ducts. Consequently, in patients with severe cholestasis related to drugs, research of early morphological signs of acute cholangitis and then of ductopenia seems to be important.