Three new complexes of the general formula: [Ni(RSO₂NCS₂)(dppe)], where R = CH₃ (1), CH₃CH₂ (2), 2-CH₃C₆H₄ (3) and dppe = 1,2-bis(diphenylphosphine)ethane, were obtained in crystalline form by the one-pot reaction of the appropriate potassium N-R-sulfonyldithiocarbimate: RSO₂NCS₂K₂ · 2H₂O and 1,2-bis(diphenylphosphine)ethane with nickel(II) chloride hexahydrate in ethanol/water mixture. The complex 1 forms monoclinic crystals (P2₁/c) with two molecules in the asymmetric unit (Z = 8), while the crystals of the complexes 2 and 3 are orthorhombic, Pbca (Z = 8) and P2₁2₁2₁ (Z = 4) respectively, with one molecule in the asymmetric unit. All complexes present a distorted square-planar environment around the Ni atom. The elemental analyses and the IR, ¹H NMR, ¹³C NMR and ³¹P NMR spectra are consistent with the formation of the nickel(II) complexes with mixed ligands.