Bariatric surgery is indicated in obese patients with a BMI ≥ 40 kg/m(2) or ≥ 35 kg/m(2) with serious comorbidities, in second intention in patients who failed to achieve significant weight loss after a well-managed medical, nutritional and psychotherapeutic treatment for 6 to 12 months, and in patients who are aware of the consequences of bariatric surgery and who agree with a long term medical and surgical follow-up. Such a treatment requires a preoperative multidisciplinary assessment and management, which includes a mandatory consultation with a psychiatrist or a psychologist that should be member of the multidisciplinary staff and participate in these staffs. Although one of this consultation's aim is to screen for the few patients who for which surgery is contra-indicated, in most cases, the main aim of this assessment is to screen for and manage psychiatric and psychopathologic disorders that could be temporary contra-indication, because these disorders could lead to poorer postoperative outcome when untreated. By explaining to the patient how these disorders could affect postoperative outcome and which benefits he could retrieve from their management, the patient will increase his motivation for change and he will be more likely to seek professional help for these disorders. In all cases, a systematic examination of the patient's personality and his/her ability to understand the postoperative instructions is essential before surgery because clinicians should check that the patient is able to be adherent to postoperative instructions. In addition to clinical interview, use of self-administered questionnaires before the consultation might help to determine which psychiatric or psychopathologic factors should be more closely screened during the consultation. Psychiatric disorders and addictions are highly prevalent in this population (e.g., mood and anxiety disorders, binge eating disorder, attention deficit hyperactivity disorder, addictions, personality disorders, pathological personality traits and dimensions), and when untreated, they can lead to poorer postoperative outcome (postoperative occurrence of psychiatric disorders, poorer quality of life, and sometimes to poorer weight loss or excessive weight rebound when the disorder is present during the postoperative period). A complementary training in addiction medicine is helpful given the higher risk for addictions in this population. Given that this evaluation is often the first meeting with a psychiatrist, an empathic and motivational approach is helpful to improve the patient's ability to request for a future psychiatric consultation during the follow-up. Some conditions are required for a high quality assessment: the objectives and expectations of the consultation should be systematically explained to the patient prior to the consultation by the physician who enquires for the assessment; it needs time; the psychiatrist should systematically be member of the multidisciplinary staff and should take part in regular multisciplinary staff meetings; patients should be seen alone to assess his/her readiness to change. After the consultation, a contact with the physician who enquires for the assessment should be systematic (e.g., use of a medical letter that sum up the main conclusions of the consultation; participation in regular multisciplinary staff meetings)., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)