The saccharinato complexes of Au(III). ZrO(II), VO (I) and UO₂(II) metal ions have been prepared and the mode of coordination of saccharin in these complexes has been investigated through their ¹HNMR and IR spectra as well as by thermal analysis. It was found that saccharin interacts with all of these metal ions in the anionic form and coordinates in a monodentate fashion through its nitrogen to Au(III), ZrO(II) and Vo(II) ions, while it coordinates to UO₂(II) ion as a bidentate ligand using its carbonyl and sulphony1 groups. A square structure has been proposed for Au(III) complexes, polymeric chain structure for ZrO(II) and VO(II) complexes and an octahedral structure for UO2-sccharin complex. The thermal properties of these complexes were shown to be consistent with the proposed structures and indicated that metallic gold, ZrO₂, V₂O₅ and UO₂SO₄ are obtained as final thermal decomposition products of these complexes, respectively.