Six novel triorganotin(IV) 2-maleimidopropanoato complexes: R 3 SnOCOCH 3 (CH)(COCH) 2 , (R: Me(1), Et(2), n-Pr(3), nBu(4), Ph(5), Bz(6) have been synthesized. Their solid-state configuration has been determined by FT IR and 119m Sn Mö ssbauer spectroscopy. The tin(IV) atom is five-coordinated in all the complexes with 2-maleimidopropanoic acid behaving as a monoanionic bidentate ligand coordinating the tin(IV) atom through a chelating or bridging carboxylate group. The solution-state configuration has been elucidated by means of 1 H-, 13 C-and 119 Sn-NMR spectroscopy which assigned a tetrahedron. Elemental analysis and FAB MS data also supported a 1:1 metal to ligand stoichiometry. The title complexes have been screened in vitro for anti-tumour, anti-fungal, anti-leishmanial and urease inhibition activities and displayed promising results.