The title compounds, chlorotris(dimethyl sulfide-κS)platinum(II) hexafluorophosphate, [PtCl(C₂H₆S)₃]PF₆, and bromotris(dimethyl sulfide-κS)platinum(II) hexafluorophosphate, [PtBr(C₂H₆S)₃]PF₆, are isomorphous and are composed of [PtX(dms)₃]⁺ complex cations (X = Cl and Br, and dms is dimethyl sulfide) and PF₆ ⁻ anions. The Pt atom is coordinated by three S atoms and one X atom in a pseudo-square-planar coordination, with Pt—S distances in the range 2.293 (1)–2.319 (2) Å. Two dms ligands have a staggered conformation with respect to the coordination plane, while the third is rotated by ∼90° compared with the orientation of the other two. The packing can be described as consisting of [PtX(dms)₃]₂(PF₆)₂ units with a centre of symmetry. In this description, the Pt^II atom has a pseudo-octahedral coordination, with four normal bonds and two long weak interactions. Density-functional theory calculations show that a conformation in which one dms ligand is not staggered is less favourable than having all three dms ligands staggered.