Several novel organotin(IV) complexes with formula SnCl 2 (CH 3 ) 2 (X) 2 , X=C 6 H 5 C(O)NHP(O)(NC 4 H 8 ) 2 (1), C 6 H 5 C(O)NHP(O)(NC 5 H 10 ) 2 (2), C 6 H 5 C(O)NHP(O)[N(CH 3 )(C 6 H 11 )] 2 (3), C 6 H 5 C(O)NHP(O)[NH-C(CH 3 ) 3 ] 2 (4) were synthesized and characterized by 1 H, 13 C, 31 P NMR, IR spectroscopy and elemental analysis. The structures have been determined for each of the four compounds. Compound 1 exists in the form of two symmetrically independent molecules in the crystalline state due to differences in their similar torsion angles. In all of the four structures there are intramolecular –Sn–Cl⋯H–N– hydrogen bonds, in addition to weak C–H⋯O and C–H⋯Cl hydrogen bonds. Both 1 H and 13 C NMR spectra show the coupling of 119/117 Sn nuclei with methyl proton and carbon atoms. The δ( 31 P) of these complexes are in upfields with respect to their corresponding reported ligands. The spectroscopic and structural properties of these complexes were compared with those corresponding ligands.