Salicylaldehyde is a commercial ligand that might be utilized as a versatile linker in constructing structures with interesting topologies. The diverse coordination ability of carboxylic group of pivalic acid is also well-known. Since nickel(II) is known to have a large single-ion zero-field splitting and often gives rise to ferromagnetic coupling, we have focused our attention especially on polynuclear Ni(II) complexes. Herein a trinuclear complex [Ni3(L)4(piv)2(CH3CN)2]·CH3CN (1), which is obtained from the reaction of nickel pivalate precursor [Ni2(OH2)(O2CCMe3)4(HO2CCMe3)4] and salicylaldehyde HL, is reported. Complex 1 was characterized by IR spectroscopy and single crystal X-ray crystallography. The IR spectrum of complex 1 shows strong and broad bands in the 1564–1534 and 1444–1405 cm^-1 regions, which are assigned to the asymmetric and symmetric vibrations of the coordinated carboxylic groups. A strong band at 1622 cm^-1 was assigned to the stretching frequency of the bonded aldehyde group. A medium strong band appears at 1219 cm^-1 and is assigned to the C-O stretching frequency. Medium-intensity bands in the regions 3000–2760 cm^-1 and bands at 1477–1325 cm^-1 are attributed to characteristic v(C–H) aromatic and aliphatic C–H stretching and bending modes, respectively. According to the crystallographic data complex 1 crystallizes in the triclinic space group P-1 with the asymmetric unit containing a linear arrangement of three Ni(II) centers.Three nickel(II) atoms are joined together by two carboxylate bridges with the Ni···Ni separation of 2.999 Å and four monodeprotonated salicylic ligands that coordinate in a bidentate bridging mode. The central Ni(II) atom of the trimer is located on a crystallographic inversion center and is coordinated octahedrally by two pivalate carboxylate oxygen atoms and four monodeprotonated salicylaldehyde ligands. Carboxylates form bridges to the peripheral Ni(II) atoms in the common bidentate syn–syn fashion, while the other four aldehyde ligands function in a bidentate mode in which two phenolic oxygen atoms of two different ligands bridge two Ni centers. In the bidentate saicylaldehyde, the second oxygen donor atoms of aldehyde group, interact with the outer nickel centers at 2.026 and 2.043 Å, respectively. These peripheral two nickel atoms have also coordinated acetonitrile molecules with the Ni–N distance of 2.177 Å. This forms also an arrangement that can be considered as a distorted NiO4N2 octahedral geometry. The thermogravimetric analysis (TGA) of compound 1 confirms its relatively high thermal stability, as it retains its integrity up to 140^oC against degradation under an air atmosphere.