Abstract The crystal structure of tetrakis(thioacetamide)nickel(II) bromide has been determined from three dimensional counter data at ambient room temperature. With λ = 0.71068A the cell constants are: a = 15.530±0.004A, b = 14.989±0.004A, c = 9.310± 0.002A, γ = 118.9±0.1°, D c = D m = 1.82 g cm −3 B2/b, Z = 4. Solution of the structure was achieved by standard heavy atom techniques and refinement by full matrix least squares with anisotropic temperature factors resulted in a final R of 0.068. The structure is composed of Ni(SCNH 2CH 3) 4 2+ molecular ions and bromide ions. The Ni atom is on a crystallographic center of symmetry requiring the Ni and its four sulfur neighbors to lie in the same plane. The bromide ions are essentially in axial positions with long NiBr distances of 3.599±0.004A. The two crsytallographically independent NiS distances are 2.216 and 2.222 both ±0.009A, while the SNiS angle is 87.3±0.4°. From the NiSC angles of 112(1)° Av. it is clear that the sulfur atom uses an sp 2 lone pair of electrons to form the metal-sulfur sigma bond. The geometry of the complex is such that the Ni, Br and thioacetamide groups related by a center of symmetry are almost coplanar, i.e., when the molecule Ni(SCNH 2CH 3) 4Br 2 is viewed down the NiBr axis. all atoms lie in one of two planes related by a 90° rotation about this axis. This orientation arises from a combination of hydrogen bonding and electronic effects.