Résumé : The synthesis and characterization by spectroscopy of several new di-n-butyltin and diethyltin 2-fluorocinnamates and 4-fluorophenylacetates are described. In vitro tests on two human tumour cell lines, MCF-7, a mammary tumour, and WiDr, a colon carcinoma, showed that two of these compounds are more active than cisplatin. Other in vitro tests performed by the NCI, USA on a panel of human tumour cell line show that one of them, bis[di-n-butyl(2-fluorophenylacetato)tin] oxide, is characterized by statistically significant Dmath image, DTGI and Dmath image sensitivities, but non-significant DH and MGDH selectivities, whereas the analogous 2-fluorocinnamate shows no such significant values.