Background and aim: Fractional CO2laser is therapeutic for acne atrophic scar, but its effect usually is limited after multiple sessions, with occasional adverse reactions. This study aimed to evaluate the efficacy and safety of a new modality combining ultra-pulse CO2laser and fractional CO2laser (multiple mode procedures [MMP]) in the treatment of acne atrophic scars. Method: From December 2017 to January 2023, a total of 103 patients with facial acne atrophic scars treated with MMP technique were retrospectively analyzed. MMP was performed for 1–4 sessions with an interval of approximately three months. Based on photographs taken before and after treatment, overall atrophic scar improvement was assessed according to the ECCA grading scale, the modified Manchester Scar Scale and the 4-point Global Assessment Scale (GAS). The safety was evaluated by the degree of pain during treatment and postoperative adverse reactions. Results: All the 103 patients received treatment and completed follow-up, with an average of two sessions. The mean ECCA score decreased from 162.7 to 93.1 with statistically significant difference (p< 0.001). The mean GAS score increased by an average of 2.3 ± 0.9. The GAS improvement more evident for “boxcar” atrophic scars (2.7 ± 0.8) than for “rolling” (2.3 ± 0.8) and “icepick” scars (1.7 ± 0.8) (p< 0.001). The average improvement scores for color, distortion and texture were 2.0 ± 0.9, 2.2 ± 0.9 and 2.3 ± 0.8, respectively. The mean pain score during treatment was 3.9 ± 0.8, and the mean duration of erythema was 30.7 ± 3.5 days. Only three patients developed hyperpigmentation at the treated site within a few months. Discussion: Ultra-pulse CO2fractional laser MMP technique can effectively improve the condition of facial atrophic acne scars with limited adverse reactions.