The coordination around the nickel ions in the title complex, [Ni3(C17H16N2O2)2(C2H3O2)2{(CH3)2SO}2], is irregular octahedral. The central nickel ion occupying the inversion centre has four O atoms from two N,N'-bis(salicylidene)-1,3-propanediaminato (SALPD2−) ligands and one O atom from each bridging acetate group. The average Ni—O distance for the central Ni ion is 2.072 (2) Å. The coordination around the terminal Ni ions, related by an inversion centre, comprises two O atoms and two N atoms from a SALPD2− ligand as well as one Oacetate and one ODMSO atom. The DMSO and acetate ligands are trans about the terminal Ni atom. The average Ni—O and Ni—N distances for the terminal Ni ions are 2.087 (2) and 2.018 (3) Å, respectively. The Ni⋯Ni bridging distance is 3.043 (2) Å.