In diving practice, divers who are suspected of suffering decompression illness (DCI) in locations remote from a recompression chamber and cannot be immediately transported to eligible settings for further treatment are sometimes treated with in-water recompression (IWR) when the equipment and technique are available. However, not all diving-related diseases require IWR, compression therapy is not feasible in all conditions. At the same time, IWR has certain risks. Therefore, at the diving site, various factors should be taken into account when IWR is chosen, and the pros and cons of IWR should be weighed for decision making. This paper briefly summarizes the conditions, risks, treatment schedules and requirements of IWR.