Psychiatric consultation should be integral to the overall evaluation of morbidly obese patients prior to any treatment but particularly before surgery. In addition to clarifying the presence or absence of diagnosable psychiatric illness, which then may affect the decision to proceed to surgery, psychiatric consultation can elicit data on psychological disturbances that are neurotic or indicative of a personality disorder or trait that may affect treatment. Important developmental and life history data contribute to an understanding of the patient and the role of eating behavior in the patient's life, which in turn aids the entire treatment team in establishing a more effective and mutually cooperative approach to treatment.