The title compound, [Zn2(C21H25N2)2(OH)2], is a binuclear zinc complex formed by two bidentate β-diketiminate (nacnac) ligands and two μ-hydroxide O atoms, bridging two mononuclear units into a centrosymmetric dimeric unit. Each Zn(2+) cation is coordinated by two N-donor atoms from the nacnac ligand and two O-donor atoms of hydroxide anions to give a distorted tetra-hedral coordination environment. The Zn-O bond lengths are 1.9643 (13) and 2.0022 (14) Å, and the two Zn-N bond lengths are 1.9696 (14) and 1.9823 (14) Å. The distance between the two Zn(2+) cations in the dimer is 2.9420 (4) Å. Although hydroxide groups are present in the complex, no classical hydrogen-bonding inter-ations are observed because of the bulky β-diketiminate ligands.