Abstract Background Postacne erythema (PAE) is a common sequela of inflammatory acne vulgaris, treatment of which has been challenging due to limited options available and the variability of results for each modality. Recently, a 577‐nm high‐power optically pumped semiconductor laser (HOPSL) initially developed for vascular lesions has shown promising results for the treatment of PAE. Aims To evaluate the efficacy and safety of 577‐nm HOPSL in the treatment of postacne erythema. Methods This was a split‐face, randomized controlled trial pilot study. Twenty‐one patients with PAE on both sides of their face were enrolled. Each subject's face sides were randomly assigned to either receive 577‐nm HOPSL treatment (QuadroStar PRO™, Asclepion Laser Technologies) using the scanner handpiece, 1mm spot size, 80% coverage, 12‐15 J/cm 2 , 30 ms, 2 passes for 3 sessions at 1‐month intervals, or no treatment at all. Outcome measures such as overall improvement, the Erythema Index (EI), and Melanin Index (MI) from 3 different areas on both treatment and control sides were assessed at baseline, and 1‐month follow‐up after each treatment session. Side effects including pain, erythema, swelling, and crusting were also recorded. Results Upon completion of the treatment period, the mean EI was significantly decreased in both treated and nontreated sides of the face ( P < .001 and P = .001, respectively). The laser‐treated sides already demonstrated significant reduction in the mean EI compared with nontreated sides at 1 month after the 2nd treatment ( P = .007). The mean MI of both sides, however, did not show any statistically significant differences from baseline, and likewise when comparing between sides. Patients reported more improvement on laser‐treated sides compared with nontreated sides. Reported side effects were limited to mild discomfort during treatment and transient facial erythema lasting approximately 30 minutes. Conclusion Patients who received treatment with the 577‐nm HOPSL had better outcomes with minimal side effects at 1 month after 2 treatments as compared to those who did not receive any treatment. Therefore, the 577‐nm HOPSL may be considered as an effective adjuvant treatment for PAE and early erythematous atrophic scars.