O-aryldithiophosphato and O-alkyldithiophosphato nickel complexes with diphosphine ligands have been synthesized by treatment of (diphosphine)NiCl2 {diphosphine=dppe (Ph2PCH2CH2PPh2), dppv (Ph2PCH=CHPPh2), dppb (1,2-(Ph2P)2C6H4)}with dithiophosphoric acid (RO)2P(S)SH (R=CH2CH3, CH2CH2Ph). The synthesis route is found to be an efficient pathway to prepare the O-aryldithiophosphato and O-alkyldithiophosphato nickel complexes. All the complexes [Ni(S2P{O}OCH2CH2Ph)(dppe)] (1), [Ni(S2P{O}OCH2CH2Ph)(dppv)] (2), [Ni(S2P{O}OCH2CH2Ph)(dppb)] (3), [Ni(S2P{O}OCH2CH3)(dppe)] (4), [Ni(S2P{O}OCH2CH3)(dppv)] (5) have been fully characterized by elemental analysis and IR, 1H, 13C, 31P NMR spectroscopies. In addition the molecular structures of 1–4 were established by X-ray crystallography.