The authors looked at 346 studies of the use of free flaps in burns and undertook a systematic review of 30 of these studies after applying inclusion and exclusion criteria. They found that the use of free flaps could be divided into early / acute or primary use and late / delayed or secondary reconstructions. The early use of free flaps was to reduce the risk of infection, and improve healing in deep burns where a large and complex tissue deficit existed, such as with exposed bone, tendons, nerves, vessels or for limb salvage. Characteristically, these were in electrical or thermal burns. Delayed use of free flaps was usually for increasing functionality or aesthetics in large scar contracture release. The authors highlighted the inclusion and exclusion criteria for their review as well as the number, types of flap, failure rate and reasons for failure in each study. The authors also devised an algorithm for the use of free flaps in burns based on timing and indications, and also illustrated the most suitable choice of flap for different areas of the body. The authors then outlined possible causes and how best to reduce the complication and failure rates in free flap surgery in burns.