INTRODUCTION: Scars are the end result of a biologic and natural process of wound repair after injury, surgery, acne, illness, burns, and infection. When skin is damaged, a fast and coordinated body response is triggered by four highly integrated and overlapping phases including homeostasis, inflammation, proliferation, and tissue remodeling. Healing of a skin wound may result in an abnormal scar if the balance among these four phases is lost during the healing process. Various topical treatments have been used for their ability to reduce unsightly scar formation. Recently, studies have shown improvement in scar appearance after treating with silicone gels containing natural herbal ingredients. The aim of this study is to evaluate the efficacy of a novel silicone-based gel containing copaiba oil (Copaderm) for prevention and/or appearance reduction of different types of abnormal scars. METHODS: This study was designed as a prospective, randomized, double-blind, placebo-controlled trial involving 42 patients with abnormal scars, divided into two groups. Each group received either a topical scar formulation consisting of copaiba oil in silicone gel or a placebo gel twice a day for 84 days. Assessments of the scars were performed at 0, 28, and 84 days following the onset of topical application using three methods: a clinical assessment using the Manchester Scar Scale, a photographic assessment to establish before and after treatment improvements, and at the end of the study period, patients completed a final satisfaction questionnaire. RESULTS: Of the original 42 patients, 32 completed the evaluation. There was a significant difference with respect to the overall score of the Manchester Scar Scale between the two groups from baseline to 84 days (P < 0.05). All patients with copaiba oil in silicone gel achieved improvement of their scars, based on overall score at 84 days. A visible scar reduction was observed with photographic assessment. Eighty-nine percent of subjects (n = 16) with copaiba oil in silicone gel rated as being satisfied or very satisfied after 84 days of treatment. CONCLUSION: Our findings support the hypothesis that copaiba oil in silicone-derivative gel was able obtain significant improvement in color, contour, distortion, and texture for different types of scar through the Manchester Scar Scale analysis. These findings contribute to reducing abnormal scar formation during the healing process.