In the neutral title complex, trans-bis(2,2′-iminodiethanolW,O)bis(isothiocyanato)nickel(II), [NiCNCS)2(C4H11NO2)2], the isothiocyanate ions and the diethanolamine molecules act as monodentate and bidentate ligands, respectively. The NiH ion exhibits a distorted octahedral configuration with crystallographically imposed inversion symmetry and NNCS-Ni-Namine and NNCS-Ni-Oamine bond angles of 88.78 (10) and 89.44 (10), respectively. The Ni-N bond distances are in the range 2.069 (3)-2.096 (2) Å. The molecules are linked by hydrogen bonds to form a three-dimensional infinite lattice. © 2000 International Union of Crystallography all rights reserved.