1 In a retrospective study, we stratified 79 patients with paracetamol hepatotoxicity into two groups according to weekly alcohol consumption below ( n = 49) or above ( n = 30) Royal College of Physicians' guidelines of 21 units week -1 for males and 14 for females. 2 Survival was lower (33%) and serum creatinine on admission higher (median 207 μmol) in patients whose alcohol consumption was above recommended guidelines than in those whose drank less than this (65.9% and 138 μmol, P < 0.01 and P = 0.027, respectively). An arterial blood pH < 7.30 on admission was also more common in those patients with a higher alcohol consumption (30% v 12.2%, P = 0.05). 3 In all patients whose alcohol consumption exceeded the guidelines, paracetamol overdose was fatal if associated with a serum creatinine greater than 300 μmol in conjunction with a prothrombin time over 100 s and grade 3 or 4 encephalopathy or a peak prothrombin time over 180 s. 4 Chronic alcohol intake above suggested limits is an adverse prognostic feature in cases of severe paracetamol overdose. This effect is partly related to increased nephrotoxicity.