This study aimed to examine the associations of lifetime traumatic experience with pre- and post-surgery eating pathology and postoperative weight-loss in a sample of bariatric surgery patients using electronic medical record (EMR) data. Pre-surgery lifetime exposure to traumatic event, pre- and post-surgery dysfunctional eating patterns, and post-operative total and excess weight losses were extracted from EMR of 200 bariatric surgery patients in 2013 and 2014. Logistic regression analyses were conducted. 60.5% of the patients (81.5% women; age=44.4±11.5 years; BMIpre=44.9±5.5 kg/m2) reported that they were exposed to a traumatic event during their lifetime. Before surgery, trauma exposure was associated with impulsive, compulsive or restrictive eating patterns (OR=2.40), overeating or disturbed eating (OR=1.55), and grazing or night eating behaviors (OR=1.72). After surgery, trauma exposure was associated with lower total weight loss at 6 months (OR=2.06) and 24 months (OR=2.06), and to overeating or disturbed eating (OR=1.53) 12 months after surgery. Bariatric surgery candidates with a history of trauma exposure could benefit from closer medical, dietetic, and/or psychological follow-up care to avoid insufficient postoperative weight loss as well as reappearance of dysfunctional eating patterns after surgery.