Reaction of the deprotonated N -thiophosphorylated thiourea 2-PyNHC(S)NHP(S)(OiPr) 2 (HL) with NiCl 2 leads to the complex [Ni{2-PyNHC(S)NP(S)(OiPr) 2 } 2 ] ([NiL 2 ]) with unprecedented 1,5,7- N , N ’ , S -coordination of the ligand. Recrystallization of [NiL 2 ]from a mixture of CH 2 Cl 2 – n -hexane or acetone – n -hexane leads to [Ni- (L-1,5,7- N , N ’ , S ) 2 ]·CH 2 Cl 2 and [Ni(L-1,5,7- N , N ’ , S ) 2 ], respectively. The latter complex, in turn, shows a temperature-induced polymorph- ism. [NiL 2 ] in solution shows a paramagnetic distorted octahedral structure where the metal center is coordinated through the nitro- gen atoms of the phosphorylamide and pyridyl group functions, and oxygen atoms of the phosphorylamide unit. Furthermore, in the solid state at low temperature, [Ni(L-1,5,7- N , N ’ , S ) 2 ] is shown from high-frequency EPR measurements to possess an S =1 ground state with large anisotropy.