Background: Acne is a very common skin disease. Scars are seen in 95% of patients with acne. Although numerous treatments have been recommended to cure acne scars, researchers are still searching for a single modality to treat the complication due to its variety in shape and depth. In other words, a combination of available methods is required to reach satisfactory results. We compared the effects of fractional carbon dioxide (CO<sub>2</sub>) laser alone and in combination with subcision. Methods: This clinical trial study was performed in Skin Diseases and Leishmaniasis Research Center (Isfahan, Iran) during 2011-12. Eligible patients with atrophic acne scars were treated with fractional CO<sub>2</sub> laser alone (five sessions with three-week interval) on right side of the face and fractional CO<sub>2</sub> laser plus subcision (one session using both followed by four sessions of fractional CO<sub>2</sub> laser, all with three-week intervals) on the left side. The subjects were visited one, two, and six months after the treatment. Patient satisfaction rate was analyzed by SPSS20. Findings: The average of recovery rate was 54.7% using the combination method and 43.0% using laser alone (P < 0.001). The mean patient satisfaction rate according to visual analogue scale (VAS) score was significantly higher with the combination method than with laser alone (6.6 vs. 5.2; P < 0.001). Bruising was only seen with the combination method and lasted for one week in 57.0% of patients and for two weeks in 43.0%. Erythema was a side effect of both methods. Post-inflammatory pigmentation and hyperpigmentation were only caused by the combination method. None of the patients had persistent side effects after six months. Conclusion: Using a combination of subcision and laser had suitable results regarding scar recovery and satisfaction rate. However, bruising, post-inflammatory pigmentation, and hyperpigmentation were the side effects of this method. In general, subcision plus laser can be beneficial in the treatment of atrophic acne scars (English).