BACKGROUND Over the past 20 years, there has been a dramatic increase in the use of autologous fat grafting to treat volume and contour defects in aesthetic and reconstructive surgery. It is generally accepted that fat grafting is safe, with good patient satisfaction. However, there are many procedural variations, and in terms of objective clinical effectiveness, the major disadvantage of this technique remains the unpredictable fat resorption rates and subsequent adverse events. Because of the rapidly evolving nature of this procedure, this review article provides an update on previous reviews by looking at the current evidence base regarding fat graft techniques and their effect on clinical outcome. METHODS A systematic review of the scientific literature listed on PubMed was performed using 20 search terms focused on harvesting, processing, reinjection, and conservation of fat grafting. An evidence-based system was used to determine eligibility for clinical and preclinical studies. RESULTS Thirty-seven articles were selected based on inclusion and exclusion criteria: five articles were clinical trials and 32 were experimental comparative studies examining human fat grafting. CONCLUSIONS This systematic review revealed a lack of high-quality data despite the increase in fat grafting over the past 20 years. At present, there is no evidence that supports specific procedural standardization. Evidence-based studies that incorporate randomized controlled, prospective, multicenter trials are required to understand which factors influence positive fat grafting clinical outcomes.