Résumé : A series of 14 derivatives of chromenyl-dihydro-thiadiazole and chromenyl-methylenethiazolin- 4-one were synthesized and screened (using the MTT colorimetric assay) for their in vitro growth inhibition capacity in six human cancer cell lines. Three cell lines displayed various levels of resistance to pro-apoptotic stimuli, while two cell lines were sensitive to pro-apoptotic stimuli. Structure Activity Relationship (SAR) analyses indicate that, of the two compound series that were investigated, chromenyl-thiadiazolines displayed higher in vitro anticancer activity than the thiazolinone derivatives. With respect to the thiadiazoline derivatives (3a-l compounds), the substitution of the exocyclic amine with a substituted-phenyl moiety increased the in vitro growth inhibition of cancer cells, and the 3-trifluoromethyl-phenyl-derivatives (3h, 3l) displayed the highest antiproliferative activity. In addition, compounds 3h, 3k and 3l overcame the intrinsic resistance of cancer cells to pro-apoptotic stimuli by induction of either cytostatic (3h, 3l) or cytotoxic (3k) effects, which was determined by quantitative videomicroscopy.