Obesity in the elderly is associated with exacerbation of functional decline (dependency), that occurs with aging, because of decreased muscle mass and strength, and increased joint dysfunction. Consequently, there is progressive loss of independence, autonomy, chronic pain and impaired quality of life. The weight loss can bring benefits in all these aspects, especially when accompanied by exercises. Elderly patients with morbid obesity may be submitted to surgical treatment, taking into account that the massive weight loss, eventually caused by bariatric surgery, may exacerbate the loss of muscle mass and nutritional complications that may bring harm to the overall health and quality of life of these patients. The functional assessment of elderly patients, candidates for bariatric surgery and the extent to which surgery can bring benefits to the patients, in the field of functionality, has still to be determined.