Background: The purposes of this study were to compare preoperative magnetic resonance imaging and intraoperative measurements of rectus diastasis and to evaluate the long-term durability of the plication of the anterior rectus fascia. Methods: Twenty consecutive cases of middle-aged female subjects undergoing lipoabdominoplasty and rectus plication were studied by magnetic resonance imaging preoperatively and between 6 months and 25 months postoperatively. Images were obtained in the T1 axial, T2 axial, sagittal, and coronal planes. Rectus diastasis was measured at the maximum. Rectus muscle thickness and width were measured, and abdominal circumferences were measured in the anteroposterior and transverse planes at the midpoint from the xiphisternum to the umbilicus and the midpoint from the umbilicus to the symphysis pubis corresponding approximately to the lumbar-2 and sacral-3 vertebral bodies. Results: The absence of diastasis can be precisely measured by magnetic resonance imaging. Postoperative diastasis was not seen in any of the cases followed up to 25 months. The preoperative magnetic resonance imaging diastasis values were consistently less than the intraoperatve measurements; however, this was attributed to muscle relaxation at surgery due to muscle relaxants during general anesthesia. There was a significant reduction in waistlines in both the anteroposterior and transverse dimensions measured by magnetic resonance imaging. Conclusions: Surgical repair of rectus muscle diastasis is a durable procedure, and magnetic resonance imaging follow-up is an excellent way to see the durability of the procedure. Magnetic resonance imaging is not operator-dependent and has no interobserver variations. It has the advantage of being a safe, radiation-free procedure with repeatability and dependability. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.