Aim of the work : To evaluate the efficacy of Erbium-YAG laser alone and in combination of platelet-rich      plasma (PRP) in atrophic post acne scars.

Patients and Methods: This study was a prospective non randomized clinical trial. 50 patients were included  in this study, examined and divided into two groups. Group A included 25 patients were subjected to 6 Erbium-YAG laser sessions over 6 months period while group B included 25 patients were subjected to 6 Erbium-YAG laser sessions plus 12 microneedling sessions with PRP over the same period. Evaluation was carried out through operating physicians, two blinded physicians as well as through patient’s satisfaction.

Results: Both modalities of treatment showed improvement of acne scars but the improvement with

combined Erbium-YAG laser and PRP was better than Er-YAG laser alone ( p value = 0.0158) with less side effects and better patients' satisfaction ( p value = 0.022).

Conclusion:  We concluded that both modalities of treatment are effective and safe in treatment of acne scars but the combination of PRP plus laser was superior to laser alone with higher response and less side effects