Obesity is a major global health problem, and its multisystem effects are inextricably linked with elevated cardiovascular risk and adverse outcomes. The cardiovascular benefits of reversing obesity in adults are well-established. Compared with other weight-loss strategies, programmes that incorporate bariatric surgery for weight loss are beneficial for sustained BMI reduction. A marked improvement in cardiovascular risk factors, including hypertension, dyslipidaemia, inflammation, and type 2 diabetes mellitus, has been observed after bariatric surgery. This broad improvement in cardiovascular risk profile has led to substantial reductions in the risk of myocardial infarction, stroke, and death. As with all procedures, the benefits of bariatric surgery must be weighed against its potential risks. Modern bariatric surgery has an excellent safety profile, but important limitations remain, including the potential for surgical complications and nutritional deficiencies, and the lifelong requirement for nutritional supplementation. Surgery should be considered in patients with severe obesity, especially those with cardiovascular comorbidities. In this Review, we summarize the current management options for patients with obesity, and discuss the effects of bariatric surgery on cardiovascular risk factors and outcomes.