Although bariatric surgery is the most effective intervention for severe obesity, a significant minority of participants fail to achieve or maintain optimal weight loss at extended follow-up. Accumulating evidence suggests that adherence to prescribed postoperative recommendations, including attendance at follow-up appointments and dietary and physical activity, is related to improved weight loss outcomes. However, adherence to these guidelines presents a significant challenge for many patients, potentially due in part to deficits in cognitive function. In this paper, we briefly examine current literature of adherence on postoperative weight loss outcomes, and review emerging evidence that the cognitive dysfunction present in a subset of obese individuals is related to weight loss outcomes following bariatric procedures. We then extend these findings, positing a role for cognitive function in moderating the relationship between adherence and postoperative outcomes.