Pulmonary embolism is the leading cause of death after bariatric surgery and represents one of the many potential life-threatening conditions after bariatric surgery. The Advanced Bariatric Life Support (ABLS) initiative was developed to teach practising bariatric surgeons, emergency physicians, and allied health professionals the need for accurate and timely diagnosis and management of life-threatening bariatric surgery complications. This case study was derived from the ABLS file and discusses the difficulty in differentiating between two major complications after gastric bypass--pulmonary embolism vs leak. Accurate diagnosis and expeditious treatment are of utmost importance to prevent death associated with these serious bariatric surgical complications.