The regularities of the extraction of some metals of transient group by 2-thionaphthol are investigated. It is established that studied cations do not change at the extraction a valence state and are extracted into the organic phase in the form of salt solvated by one molecule of extractant and solvating reagent MA₂·НА·L. By results of researches a number of extractability of the studied cations is established: Cd²⁺>Pb²⁺>Zn²⁺>>Ni²⁺.