One hundred and fifty-three consecutive patients referred to the Royal Prince Alfred Hospital for consideration of gastric bariatric surgery (surgery for obesity) were assessed pre-operatively by the one psychiatrist, with regard to social, psychological and psychiatric factors. Fifty-one patients (33%) were considered to be uncomplicated from a psychiatric point of view. Eighty-eight patients (58%) had identifiable psychopathology and 14 patients (9%) were of doubtful motivation. Thirty patients (20%) were rejected from the treatment programme after the initial assessment because of overt psychiatric illness, severe situational stress, insufficient motivation or lack of significant support. Six of these patients after further assessment or after responding to psychiatric treatment were reviewed and found suitable for a bariatric operation. Of the 113 patients who had a bariatric procedure performed, 17 patients (15%) required postoperative psychiatric management. while the need for psychiatric assessment of patients presenting for bariatric surgery is disputed by some, our experience would indicate that careful pre-operative screening by a liaison psychiatrist, familiar with morbid obesity and its surgical management, is useful in any bariatric surgical programme. Such screening should identify and enable exclusion of the small number of patients who for psychiatric reasons, are poor risk candidates. A number of other patients in whom identifiable psychopathology will be discerned, will require pre-operative psychiatric management. While such a programme will decrease postoperative psychiatric problems, these will not be eliminated in the morbidly obese, and the assessing liaison psychiatrist will have a valuable role to play in the collaborative postoperative management of such patients.