INTRODUCTION: Persons with bipolar disorder (BD) have an increased risk of obesity and associated diseases. Success of current behavioral treatment for obesity in patients with BD is inadequate. METHODS: Existing literature on bariatric surgery outcomes in populations with BD were reviewed, and needed areas of research were identified. RESULTS: Knowledge about bariatric surgery outcomes among patients with BD is limited. Available evidence indicates that bariatric surgery is a uniquely effective intervention for achieving and sustaining significant weight loss and improving metabolic parameters. Notwithstanding the benefits of bariatric surgery in nonpsychiatric samples, individuals with BD (and other serious and persistent mental illnesses) have decreased access to this intervention. Areas of needed research include: (1) current practice patterns; (2) metabolic course after bariatric surgery; (3) psychiatric course after bariatric surgery; and (4) mechanisms of psychiatric effect. CONCLUSION: The considerable hazards posed by obesity in BD, as measured by illness complexity and premature mortality, provide the basis for hypothesizing that bariatric surgery may prevent and improve morbidity in this patient population. In addition to physical health benefits, bariatric surgery may exert a robust and favorable effect on the course and outcome of BD and reduce obesity-associated morbidity, the most frequent cause of premature mortality in this patient population.