Abstract The crystal structure of tetrakis(thiourea)platinum(II) chloride has been determined from 1991 counter measured intensities collected at room temperature. The structure was solved by heavy atom methods and refined by full matrix least-squares including anisotropic temperature factors and anomalous dispersion corrections for Pt, Cl and S to a final R of 0.054. The structure may be described in terms of Pt[SC(NH 2) 2] 4 2+ ions and Cl− anions with van der Waals interactions and NH - - - Cl hydrogen bonding between ions. The shortest PtCl distance is 3.773(7) Å. The PtS 4 is almost square planar with an 0.1 A displacement of S atoms from the least-squares plane. The entire cation has approximately D 2 symmetry. The average PtS distance is 2.313 A (all within 2 esd's, ± 0.006 A). One halogen seems to be involved in five hydrogen bonds (NH---Cl, 3.5 A or less) and the other in three hydrogen bonds. The hydrogen bonding scheme seems to be the reason for the structural differences from the analogous Pd compounds.