The synthesis of cobalt(II)complexes with benzil isonicotinoyl hydrazone(BINH) ligand have been reported. The ligand was prepared by condensing benzil and isonicotinic acid hydrazide. Infrared spectra show that the free ligand exist both in keto and enol form at room temperature. Complexes of the composition [Co(BINH) X2].nH2O and [Co(BIN) X2].nH2O (X = Cl-, NO3 - or SO4 2- ) have been prepared at different pH .The ligand (BINH) acts as a neutral tetradentate NNOO donor both in keto and enol form. Characterization of the above complexes has been made on the basis of their elemental analyses, infrared spectra, magnetic measurements, conductivity data, and electronic spectra. The electronic spectrum of cobalt(II) complexes in acid medium indicated the distorted octahedral and square planar in alkali medium around the cobalt(II) ion.