The feasibility of the addition of CCl4 to linear and cyclic olefins and dienes in the presence of chromium and ruthenium complexes was established. The influence of water as a nucleophilic additive and the influence of the olefin nature, the catalyst central atom, and its ligand environment on the reaction selectivity and product yields were investigated. It was shown that the addition of water to chromium and ruthenium catalysts leads to the hydrolysis of the chloromethyl group in the resulting 1,1,1,3-tetrachloro derivatives, yielding the corresponding hydroxy derivatives and increasing the selectivity for the formation of (1 + 1) adducts, which is caused by the formation of hypochlorous acid playing the role of a coactivator of the addition of CCl4 to alkenes.