Median arcuate ligament syndrome (MALS) is a condition characterized by chronic abdominal symptoms associated with median arcuate ligament compression of the celiac artery. The selection of patients is difficult in the management of MALS. This study aimed to identify factors that predict outcomes of surgical and nonoperative treatment in these patients.Patients referred with a possible diagnosis of MALS between 1998 and 2013 were identified retrospectively. Only patients with chronic symptoms and radiologically confirmed celiac artery compression were included. The clinical features, investigations, and management were documented. Outcome was assessed using the Visick score, Gastrointestinal Symptom Rating Scale, and 12-Item Short Form Health Survey by telephone interview and review of medical records.There were 67 patients, 43 (64%) treated surgically and 24 (36%) managed without surgery, with a median follow-up of 25 months and 24 months, respectively. After surgical treatment, 16 (37%) were asymptomatic, 24 (56%) were partially improved, 3 (7%) had no changes in symptoms, and none had worsening of symptoms. Postexertional pain predicted improvement after surgery (P = .022). Vomiting (P = .046) and unprovoked pain (P = .006) were predictors of poor surgical outcome. After nonoperative management, 1 (4%) was asymptomatic, 7 (29%) were partially improved, 12 (50%) had no changes in symptoms, and 4 (17%) had worsening of symptoms. No outcome predictors of nonoperative treatment were identified.MALS was more likely to respond to decompression if patients had postexertional pain. Patients who presented with vomiting and unprovoked pain were unlikely to respond to surgery. In contrast with previous studies, postprandial pain was not found to be predictive of outcome.