This study aim to assess the efficacy of Er-YAG laser 2940nm and PRP as a single line of treatment in comparison with combined treatment in atrophic post acne scars.

Inclusion Criteria:

• patients with atrophic post acne scars classified on the basis of Goodman and Baron's Qualitative classification, no active acne lesions and patients with atrophic scars only

Exclusion Criteria:

• patients with positive history of keloidal tendency, positive history of bleeding tendency, platelet disorder, patients with any acute infection on face like, herpes, folliculitis, patients with HIV, HBsAg, patients with a history of autoimmune diseases or patients on immunosuppressive drugs.