Abstract Bariatric surgery leads to significant weight loss in the obese patient. Exercise has been shown to improve weight loss and body composition in non-surgical weight loss programmes. The role of exercise to improve weight loss following bariatric surgery is unclear. The objective of this review is to systematically appraise the evidence regarding exercise for weight loss in the treatment of obesity in bariatric surgery patients. MEDLINE, AMED, CINAHL, EBM Reviews (Cochrane Database, Cochrane Clinical Trials Register) were searched, obesity-related journals were hand-searched and reference lists checked. Studies containing post-surgical patients and exercise were included with the primary outcome of interest being weight loss. A literature search identified 17 publications exploring exercise in bariatric surgery patients. All studies were observational; there were no intervention studies found. The most commonly used instruments to measure activity level were questionnaires followed by telephone interview, surgeon reporting and clinical notes. There was a positive relationship between increased exercise and weight loss after surgery in 15 studies. Meta-analysis demonstrated in patients participating in exercise a standardised mean of 3.62 kg (CI=1.28, 5.96) greater weight loss compared to the minimal exercise groups. Observational studies suggest that exercise is associated with greater weight loss following bariatric surgery. Randomised controlled trials are required to further examine this relationship.