The title compound, [Ni(acac)2(Im)2] (acac = acetylacetone), has been obtained by the reaction of Ni(acac)2 with imidazole ligand in the ethanol solvent. The blue crystal is of triclinic, space group Pi with a = 7.472(2), b = 9.456(2), c = 13.823(3) ? a = 85.55(3), = 89.03(3), ? = 80.63(3)o, C16H22N4NiO4, Mr = 393.09, V = 960.7(3) 3, Z = 2, Dc = 1.359 g/cm3, F(000) = 412, = 1.036 mm-1, R = 0.0549 and wR = 0.1615. The crystal structure consists of two disconnected structural units. Each Ni atom coordinated by two N atoms from two imidazole ligands and four O atoms from two acetylactone ligands adopts a slightly distorted octahedron. The structure characterization was performed by means of IR, UV, TG, elemental analysis and single-crystal X-ray analysis. The thermal gravity (TG) data indicate that thermal decomposition of the title compound takes place in two steps, and the residue is NiO.