BACKGROUND: Ablative resurfacing lasers are effective for treatment of acne scars, but they have a high risk of complications. Fractional lasers have less severe side effects but more moderate efficacy than ablative devices. Studies were performed in individuals with Fitzpatrick skin type I to VI. OBJECTIVE: To determine the efficacy and safety of an erbium 1,550-nm fractional laser in the treatment of facial acne scars in Fitzpatrick skin types IV to VI. METHODS: We conducted a prospective, single-blind, randomized trial in patients with acne scars (n=15), skin type IV to VI, with a 1,550-nm erbium fractionated laser. Patients were divided into two groups; one was treated with 10 mJ and the other with 40 mJ. Five monthly laser sessions were performed. A patient questionnaire was distributed. RESULTS: There was a significant improvement in the acne scarring and overall appearance (p<.001). No significant difference was found between 10 and 40 mJ. Patients were highly satisfied with their results. Significant postinflammatory hyperpigmentation was seen; pain was significantly higher in darker skin. CONCLUSIONS: Fractional photothermolysis is effective for the treatment of acne scars, but practition-ers should be aware of the higher incidence of pain and postinflammatory hyperpigmentation in individuals with skin types IV to VI.