The combination of pharmacophoric nuclei with different targets has been a strategy for the development of new drugs aimed at improving cancer treatment. A series of ten novel phthalimido-thiazolidine-2-4-dione derivatives were synthesized by two different synthetic routes. The compounds were tested and evaluated in vitro, through antineoplastic activities against cancer cells. Cell cycle analyzes and clonogenic assay were also performed. In addition to these tests, in silico predictions were performed. The synthesized FT-12 compound (9j) exhibited antiproliferative activity against Panc-1, Sk-mel-28 and PC-3 cells. FT-12 reduced the ability to form new clones, also caused irreversibility in cell cycle, inducing arrest in phase S. Besides, the compound (FT-12) caused necrosis and apoptosis. The results suggest that phthalimido-thiazolidine derivatives may be useful in cancer therapy, highlighting compound FT-12 (9j) as a promising candidate. More studies must be carried out to confirm the viability.