A male patient was admitted to hospital 12 h after self-poisoning with mercuric chloride. He suffered multiple complications including acute renal failure, ulcerative colitis, anaemia, disseminated intravascular coagulation, chronic sepsis and severe weight loss. Initially he responded well to resuscitative measures and intensive supportive therapy, which included ventilation of the lungs, haemodialysis, dimercaprol, antibiotics, parenteral feeding and gastrointestinal surgery. Unfortunately the sepsis was never satisfactorily eradicated despite satisfactory serum concentrations of the appropriate antibiotics. On day 43 after poisoning he had a grand mal fit; after this there were focal neurological signs and on lumbar puncture he was found to have a raised protein concentration and raised pressure in his cerebrospinal fluid. The condition of the patient rapidly deteriorated and on day 47 he died. Post-mortem examination revealed a large cerebellar abscess. The literature on mercury poisoning is reviewed.