Ni(lI) complexes of 5(3)-methylpyrazole-3(5)-carbohydrazide (MPCH) and its deprotonated anion (MPC) have been isolated and characterised in the solid state. Magnetic and electronic spectral features classify both the bis-complexes Ni(MPCH)2X2.2H20 and the mono-chelates Ni(MPC)X.2H20[X = C1, Br, I, NO3, BF4, CIOa, SCN or 0.5SO4] as grossly octahedral ones. The IR spectra indicate that in the bis-derivatives the ligand is bidentate through the pyrazolyl-ring nitrogen and the ketonic oxygen of the hydrazide residue and that in the monochelates. the deprotonated ligand functions primarily as a (ONN) tridentate finally forming polymeric quasi-octahedral species through involvement of additional donor site (amide-nitrogen) of the hydrazide residue; the counterion (X) is coordinated in majority of the complex species.