A history of life events in the three months before onset of illness was taken in a group of schizophrenic and a group of depressed neurotic in-patients. The Expressed Emotion (EE) of the patients' key relatives was measured. There was no difference between the schizophrenic and depressed patients in the rate of events in the three month period before onset or in the proportion of undesirable events. However, the two groups exhibited significantly different patterns of interaction between life events and relatives' EE. Schizophrenic patients living with high EE relatives had a low rate of life events compared with those living with low EE relatives, whereas depressives living with high criticism relatives had a high rate of events compared with those living with low criticism relatives. The implications of these findings are discussed in relation to schizophrenic and depressive patients' differential vulnerability to environmental stress.