Mononuclear and binuclear copper(II) and nickel(II) complexes with 5-methyl-2-hydroxyacetophenone N(4)-substituted thiosemicarbazones have been prepared and characterized. IR and 1 H NMR spectra of the N(4)-substituted thiosemicarbazones and their metal complexes, as well as ESR spectra of the mononuclear copper(II) complexes, have been obtained. The crystal structures of 5-methyl-2-hydroxyacetophenone N(4)-dimethylthiosemicarbazone and a representative binuclear copper(II) complex have been acquired, and their structural features are compared to related thiosemicarbazones and previously reported binuclear copper(II) thiosemicarbazone complexes.