Severe obesity affects the health and quality of life of 4 million Americans. The major cost of treating severe obesity and its associated comorbidities of hypertension, diabetes, cardiovascular disease, pulmonary insufficiency, cancer, and degenerative arthritis as well as the poor long-term results of medical, drug, and behavioral therapy has increased the numbers of patients being referred for surgical treatment. Gastric bypass and vertical banded gastroplasty are the two procedures recommended for severely obese patients. These operations currently have low morbidity and mortality. Surgery should be considered adjuvant therapy and must be part of a multidisciplinary approach. The significant long-term weight control resulting from the surgical therapy is associated with improvement and, often, resolution of comorbidities, including diabetes, hypertension, hyperlipidemia, and pulmonary insufficiency.