This paper highlights several methods of C-C and C-H transfer reactions in aqueous media. In all cases, thiols play the role of the reducing agents. A variety of useful synthetic methodologies were also described, which occurred mainly via a free radical non-chain transfer processes. The potential usefulness of free radical reactions in water is demonstrated by ever-increasing studies over the last 5 years. In addition, a cis-trans lipid isomerization process under photoand gamma-irradiation conditions was reported. The complexity of the selective generation of thiyl radical in aqueous media and/or in biological milieus makes this topic highly important in chemistry, biology and medicine.