A total of 179,000 bariatric surgeries were performed in the USA in 2013, with Roux-en-Y gastric bypass (RYGP) comprising 34 % and laparoscopic sleeve gastrectomy (SG) 42 % of the procedures [1]. This chapter focuses on the complications from RYGB, SG, laparoscopic adjustable gastric band (LAGB), and biliopancreatic diversion with duodenal switch (DS) that occur within the first 30 days. Given that surgical intervention may be required, patients presenting with complications in the early postoperative period may benefit from transfer to their bariatric surgeon or a bariatric surgery center. In the event of peritonitis or hemodynamic instability, prompt transfer and treatment may not be feasible. Therefore, it is important for general surgeons to be able to recognize and manage acute bariatric surgical complications. Initial evaluation should proceed with special attention to the type of bariatric procedure, giving intravenous fluid resuscitation and correction of electrolytes, obtaining a complete blood count with coagulation markers, and possibly obtaining appropriate imaging.