Introduction: Orthognathic Surgery (OS) aims to correct deformities of the bones of the maxilla and mandible. In this scenario, fat grafting is a powerful tool for corrections and also for facial aesthetic improvement together or after OS. The benefits of fat grafting during orthognathic surgery; to maximize aesthetic results, minimize swelling and optimize wound healing. Objective: To analyze the main clinical studies on the benefits and risks of facial fat grafting in orthognathic surgery, to know the current state of the art. Methods: It followed a systematic literature review model on the main clinical findings of orthognathic surgery and fat grafting, according to the rules of PRISMA. The research was carried out from July to September 2022 and developed based on Google Scholar, Scopus, PubMed, Ovid, Scielo, and Cochrane Library, using scientific articles from 1986 to 2022. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results: 123 studies were analyzed, with only 32 medium and high-quality studies selected, according to GRADE rules, and with risks of bias that do not compromise scientific development, based on the Cochrane instrument. Studies have shown that OS aims to establish harmonious facial esthetics, excellent functional occlusion, and improved airway conditions. As an important adjunct to OS, fat grafting is becoming more and more common due to its antiinflammatory role and effects on facial swelling. High patient satisfaction with the results. Postoperative swelling resolved at week 12 in the fat graft group and persistent edema. The edema decrease over time, with almost complete resolution within 1 year, improvement in facial morphology, function, quality, and skin texture in most of their patients. The use of assisted lipo transfers containing mesenchymal stem cells derived from adipose tissue, enables improvement in skin quality, smoothing of wrinkles, pore size, and attenuation of pigmentation and resolution of scars. Furthermore, enrichment of the lipoaspirate with stem cells derived from adipose tissue increases graft retention. Conclusion: Most of the studies analyzed in this review study showed that fat grafting in orthognathic surgery is a safe and effective tool to improve wound healing, improve aesthetic results, present an anti-inflammatory effect and reduce edema.