The aim of the present study was to describe lung cancer patients' causal attributions and examine their associations with adaptation. Methods were based on semi-structured interview, content analysis, self-reports, interviewer ratings and standardized questionnaires. 'Smoking cigarettes' and 'toxins in the work place' were the most commonly mentioned possible causes. Patients who made a psychosocial causal attribution suffered greater emotional distress, were more depressed, and less hopeful than other patients. They were also more likely to be rated as showing a maladaptive way of coping with illness. The implications of these findings for psychosocial care are discussed.