Obesity is a chronic disorder with numerous manifestations as well as pandemic occurrence on a global scale. One-anastomosis gastric bypass (OAGB) is a safe and effective surgical procedure for the treatment of obesity and metabolic diseases. Revision surgery may be necessary due to postoperative issues, such as protein-calorie deficiency, weight increase, or inadequate weight loss. This case describes a 40-year-old female patient who came to our service due to protein-caloric malnutrition, with a history of OAGB. The patient underwent revision surgery for OAGB reversal. One year after surgery the patient had a body mass index (BMI) of 25; today she is healthy, consumes a regular diet, and has no associated complications.