Background: Acne patients are always concerned with scars and may suffer from depression and suicidal thoughts and even attempts. The commonest type is atrophic scars that could be ice pick and rolling or boxcar scars. Many therapeutic modalities are used for amelioration of the post acne scars. Objectives: This study aimed to compare between whole facial-area versus Focal Acne Scar Treatment (FAST) treatment techniques of atrophic post-acne scars using fractional carbon dioxide light amplification by stimulated emission of radiation (CO₂ LASER) Patients and Methods: This split face comparative study was held in Dermatology and Venereology Department, Ain Shams University. It included twenty atrophic, post-acne vulgaris adult scar patients.  Each patient received one fractional CO₂ LASER resurfacing session; the right side of the face was treated by the whole area, while the left by the FAST technique. Before and after results evaluation was done by 16 mega pixel Samsung UK S6 edge and Antera 3D digital cameras' photographs, patients' satisfaction and physician blinded scoring. Results: Antera texture (roughness) mode showed statistically highly significant improvement in acne scars using both whole and focal fractional CO₂ laser treatment, but no statistically significant difference could be detected between both modalities. Patients' and researchers' assessments of post-treatment results showed statistically non-significant differences in both modalities. Conclusion: Treatment of post-acne atrophic scars with fractional CO₂ laser showed statistically highly significant improvement by both techniques and both were equally preferable.