To our knowledge, long-term, objective results of lip augmentation using superficial musculoaponeurotic system (SMAS) tissue transfer beyond 1 year have not been previously described. To evaluate the efficacy, longevity, and safety of lip augmentation using SMAS tissue transfer. A retrospective single-blind cohort study was designed to evaluate all patients who underwent surgical lip augmentation using SMAS following rhytidectomy between January 1, 2000, and November, 16, 2015, at a private facial plastic surgery practice in Birmingham, Alabama. Preoperative photographs of each patient served as controls and were compared with postoperative photographs at 3 months, 1 year, and 5 years after lip augmentation. A total of 104 images (from 26 individual patients) were reviewed by 12 blinded observers using a validated lip augmentation grading scale. Lip augmentation using SMAS. Median lip volumes of all patients at each postoperative interval (3 months, 1 year, and 5 years) compared with preoperative lip volumes. Secondary outcome measures included postoperative complications. A total of 423 patients were identified who underwent surgical lip augmentation using SMAS. Sixty patients with approximately 5 years or more of postoperative photographs were reviewed for complications. Twenty-six patients had 3-month, 1-year, and 5-year postoperative follow-up photographs and were included in the photographic evaluation. The mean age of these patients at the time of surgery was 54.6 years (range, 41.2-80.6 years. Fifty-nine of the 60 patients (98.3%) were female. Two of 60 patients (3.3%) with 5 years or more of postoperative follow-up developed complications requiring intervention. Both the superior lip and the inferior lip showed statistically significant increases in volume at 3 months, 1 year, and 5 years (P ≤ .004 for the superior lip after 5 years; P ≤ .001 for all other comparisons) after SMAS lip augmentation. The greatest median increase was observed in the superior lip at 3 months, while the smallest median increase was observed for the inferior lip at 5 years. The degree of increase in median volume seemed to weaken slightly over time, but remained statistically significant even at 5 years. SMAS lip augmentation is an effective and safe method for lip augmentation that can yield natural, long-lasting results with minimal risk. The degree of augmentation tends to fade slightly over time, but remains significant for at least 5 years postoperatively. 3.