The synthesis of monomer, dimer, tricyclohexyl- and tripheilyl-tin(IV) complexes with phthalimido-4-methyl pentanoic acid (PMPA) are described and characterized by FT IR, CHN analyzer, H-1, C-13 Sn-119 NMR and Sn-119m Mossbauer spectroscopic techniques. In vitro ED50, anti-tumor (phytotoxic), anti-yeast, blood pressure and heart rate effect, and bactericidal, fungicidal as well as analgesic bioassays of complexes are also be carried out. The ligand (PMPA) shows excellent analgesic activity while the dimer exhibit strong biocidal and excellent anti-tumor behavior besides of tri-organotin(IV) complexes. (c) 2006 Elsevier B.V. All rights reserved.