The use of haemodialysis to successfully treat a potentially fatal mixed overdose of chloral hydrate, phenelzine and chlordiazepoxide is described. The plasma clearance of chloral, measured as trichlorethanol, was 68ml/min, at a blood flow rate of 200ml/min. Despite the advent of charcoal and resin column haemoperfusion, we believe haemodialysis remains a safe, relatively cheap and highly effective means of treatment in such situations. The toxicology and indications for haemodialysis are discussed.