Introduction: Post acne scars are a common avoidable complication of acne vulgaris. The face is the most common site affected by acne vulgaris and scars so that it has an important impact on the quality of life of these patients.
 Treatment of these scars is so important for acne patients but although different treatment methods are available no single treatment has been universally effective. Microdermabrasion (MDA) with infusion is a new modification of MDA technology that includes exfoliation with a dermal infusion.
During this procedure, topical products are introduced into the skin at the time of or immediately after exfoliation.
Aim of the work: Evaluation of efficacy of diamond microdermabrasion with topical vitamin  C in the treatment of acne scars.
Patients and Methods: Ten patients with atrophic post-acne scars in the face attending the outpatient clinic of  Dermatology in Sohag University Hospitals between April 2018 to September 2018 were subjected to six diamond microdermabrasion sessions plus administration of topical vit. C (during the session of diamond microdermabrasion and daily topical application in between sessions). The sessions of diamond microdermabrasion were two weeks apart. patients were evaluated at each session and one month after completion of sessions for both efficacy and safety of the procedure.
Results: The mean ± SD of the patients' age in the study were 26.00 ±5.81years old. Nine females and one male with a mean duration of acne scars ± SD7.45±4.73 years, 80%% of patients suffered psychological distress from their acne scars. At the end of the study duration, none of the patients achieved grade reduction in their Goodman and Baron qualitative grading score and 100% of patients had poor ( <25%) satisfaction.
Conclusion: Multiple  sessions of diamond  microdermabrasion with topical vitamin C during sessions and daily application is an ineffective treatment for post-acne atrophic scars