Copper(II) acetate is a well-known dinuclear metal complex, having a lantern-type (or paddlewheel-type) core composed of two copper(II) atoms and four acetato bridges [1]. On the other hand, nickel(II) acetate is known as a mononuclear metal complex composed of one nickel(II) atom and two acetato ligands. Although a lantern-type dinuclear core was also found in some adducts of nickel(II) pivalate [2,3], the structure of the parent complex nickel(II) pivalate has not been elucidated yet. Therefore, we tried to reveal the molecular structure of nickel(II) pivalate by crystallizing the parent complex using various organic solvents. In this study, we isolated a crystalline material by recrystallizing the product from hexane. The X-ray structure analysis of the isolated compound revealed a different dinuclear nickel(II) molecule from the lantern-type dinuclear core. Interestingly temperature dependence of magnetic susceptibilities (4.5—300 K ) of the compound showed a ferromagnetic property. Herein, we report on the crystal structure and magnetic property of this compound.