Analysis of data derived from 130 reports of jaundice occurring after anaesthesia with halothane showed a significant relation between the number of exposures to this anaesthetic and the rapidity with which jaundice develops after exposure. This is considered to provide strong evidence of a cause-effect relationship between the use of halothane and jaundice. Out of 114 patients with complete anaesthetic histories 94 (82%) had been exposed more than once; of those so exposed 80% had been anaesthetized with halothane more than once within 28 days. Altogether 66 (51%) of the 130 patients died.