BACKGROUND: Cell-based therapies are popular in the field of reconstructive surgery. The stromal vascular fraction (SVF), comprised of mature adipocytes or blood, reportedly has a regenerative effect; however the mechanism remains unclear. This study aimed to prove the viability and effectiveness of using SVF in scar treatment. METHODS: This prospective double-blind study involved 20 patients who visited an outpatient clinic for 2 years, from July 2016 to July 2018, and underwent scar revision for traumatic or surgical scars. After scar revision surgery performed by a single surgeon, patient scars were divided into experimental and control sides. The subcutaneous layer of the experimental and control sides were injected with 0.1 mL/cm of SVF and normal saline, respectively. Each side was evaluated using the Patient and Observer Scar Assessment Scale (POSAS) before and six months after the surgery. RESULTS: Of the 20 patients who underwent scar revision surgery and SVF treatment, 4 dropped out for personal reasons. In 11 of 12 POSAS items, the experimental side showed significant improvements compared to the control side. CONCLUSIONS: Although more research is needed, autologous SVF is a valuable source of regenerative medicine that can be swiftly and inexpensively prepared from human fat tissue.