Recent advances in free-radical chemistry have expanded the versatility and flexibility of carbon–hydrogen bond formation in aqueous media. This review highlights progress made in the last decade to “tame” reactive free-radical species in aqueous-phase reactions. Detailed are a broad range of synthetically useful transformations and their application in synthesis, DNA structural probing and isotope labelling. The review provides some practical hints useful for the design of high-yielding free-radical reactions in aqueous media.