Introduction: The ECCA grading scale (échelle d’évaluation clinique des cicatrices d’acné) is a tool designed to help dermatologists to assess the severity of acne scars and to standardize the discussions about the treatments of scars. Methods: We developed an acne scar clinical grading scale called ECCA, which consists of 6 items designed to assess easily and quickly the severity of acne scars by a global score. The interobserver reliability of the ECCA grading was statistically validated. Results: The statistical analysis showed the interinvestigator reliability of the ECCA grading scale among 7 dermatologists who used it on the same group of 10 acne patients. Conclusion: ECCA is a new tool which will now be available for dermatologists to use in their everyday practice and for clinical trials evaluating the efficacy of treatments on acne scars.