Two sets of findings of an exploratory psychiatric study of surgical patients are presented. Patients were randomly selected from the surgical wards of a public general hospital, and were found to be representative of the total surgical population of the hospital with regard to age, sex, duration of admission, whether or not surgery was performed, type of surgery, number of previous operations, and whether or not there had been any previous contact with psychiatrists. Psychodiagnostic interviews, psychological tests, and social histories were attempted for each patient. Findings were of diagnosable mental disorder in 86% of the patients, with insufficient data in 4.5% and no psychiatric illness in 9.5%. In 48.5% of the cases there was a significant relationship between the surgical status of the patient at the time of presentation to the surgeon for treatment, and emotional disorder; in 44% there was no demonstrable relationship; in 7.5% data were insufficient. Some problems raised by the unexpectedly high incidence of mental disorder in surgical patients, and the relationship between emotional disturbance and surgical illness, are presented.