Although gastric bypass surgery continues to grow in popularity for weight loss and weight maintenance in the morbidly obese, there has been little attention given to the imaging of complications associated with these surgeries. The purpose of our study is to demonstrate the variety of gastric bypass surgery complications that can be identified radiographically, with attention to the more unusual complications. This study was performed with institutional Internal Review Board approval. We performed a 5-year retrospective review of all patients who had undergone gastric bypass surgery, had complications of the surgery, and had studies performed in our department to image these complications. These studies consisted of contrast fluoroscopy and CT. We identified the more common complications of anastomotic stenoses and anastomotic leaks. We also identified six unusual complications as follow: (1) internal herniation through the small bowel mesentery, (2) internal herniation through the transverse mesocolon, (3) external herniation through the abdominal wall incision, (4) enterocutaneous fistulas, (5) antiperistaltic construction of the Roux-en-Y, and (6) incorrect anstomoses of the Roux limbs resulting in a Roux-en-O configuration. Our findings show that a thorough understanding of expected postoperative bowel configuration is essential in the evaluation of these patients. In addition, fluoroscopic evaluation should assess not only anatomy, but also motility.