The eight possible isomers of dichlorobis(dibutyl sulfide)platinum(II) have been prepared and characterized, six of them in a pure state ( cis- and trans-n; cis- and trans-iso; and cis- and trans-sec.). We have separated some of the geometric isomers from each other, some of the ligand isomers from each other, and some of both types from each other by thin-layer chromatography.