As bariatric surgery for the treatment of morbid obesity enters its sixth decade, much has been and continues to be learned from the results of several key bariatric operations, particularly the Roux-en-Y gastric bypass. Because of the obesity epidemic and development of the laparoscopic approach, bariatric procedures have increased exponentially in the past decade and are now among the more commonly performed gastrointestinal operations. Emerging data support the role of bariatric surgery as an effective treatment for improvement or remission of type 2 diabetes, hypertension, dyslipidemia, and multiple other comorbid conditions that accompany obesity. The mechanisms involved in the remission of these conditions, however, remain poorly understood and constitute an exciting area of research. This article delineates the current types of bariatric surgery, their respective outcomes, and their impact on obesity-related medical comorbidities.