Résumé : Eleven di-n-butyltin(;IV) derivatives of the type (;a) (;C4H9)2(;XYC6H3COO)2Sn or (;b) {[(;C4H9)2(;XYC6-H3COO)Sn]2O}2 (;X, Y = H, 2-OH, compound 1a; H, 2-OCH3, compounds 2a and 2b; H, 2-OCOCH3, 3a; 2-OH, 3-OCH3, 4a; 2-OH, 3-CH3, 5a; H, 3-OCH3, 6a and 6b; H, 3-N(;CH3)2, 7a; H, 2-(;CF3), 5-(;CF3), 8a and 3-OCH3, 4-OH, 9a) have been prepared and characterized by 1H, 13C and 119Sn NMR, Mössbauer and mass spectroscopy. The in vitro antitumour activity of these compounds against MCF-7 human tumour cells was higher than that of cis-platin, but only three compounds, 4a, 8a and 9a, scored better than cis-platin against the WiDr cell line.