Background and Objective : Atrophic scars are the most common complication of acne. Many modalities are proposed but each does not yield satisfactory clinical outcomes. Among therapeutic modalities of acne scars, subcision is a simple, safe procedure with a different and basic mechanism for correcting atrophic and depressed scars. However, there are few reports about such procedure. This study performed to evaluate the effect of subcision treatment on atrophic acne scar. Methods : Five patients with atrophic acne scars of various types(rolling, superficial and deep boxcar, pitted and icepick) were treated by superficial dermal undermining with 25~27 gauge needles. We used GASC(Global Acne Scarring Classification). Satisfaction degree was asked from the patients. Results and Conclusions : After observing patients satisfaction, comparing case photos and GASC, it can be considered that subcision treatment brings great results when performed on atrophic post acne scars.