BACKGROUND: The appearance and symptoms of scars can cause significant distress to patients. OBJECTIVE: To assess and compare efficacy of the 1,500-nm nonablative fractional laser (NAFL) and 10,600-nm ablative fractional laser (AFL) in reducing symptoms and improving the appearance of traumatic or surgical scars. MATERIALS AND METHODS: Single-center prospective, randomized, blinded, split-scar study was conducted on 100 patients with a scar obtained through trauma or surgery. Three treatments of NAFL or AFL were administered to each half of the scar at 4-week intervals. Scars were self-rated by the patient using the Patient and Observer Scar Assessment Scale and a satisfaction score and objectively evaluated by blinded dermatologists using the Manchester Scar Scale and visual analog scale. RESULTS: Blinded observers found no statistically significant difference in scar appearance. Patient rating showed improvement of scar appearance (p < .0001). Pain was worse after treatment with AFL (p = .0492). Overall, there was no statistically significant evidence of one laser being superior or inferior to the other for patient and blinded observer scores (p = .3173 and p = .2513, respectively). CONCLUSION: Scar treatment with AFL or NAFL is associated with high patient satisfaction. Objective evaluation of scars did not identify improvement in scar appearance.