There are limited studies centring on the potential of thiazolidin-4-ones as anticancer agents. In this study, a new series of 2-(3-substituted-1H-pyrazol-4-yl)-3- (3-substituted-5-sulfanyl-1,2,4-triazol-4-yl)-1,3-thiazolidin-4-one (4a–o) have been synthesized by cyclo-condensation reaction of 5-substituted-4-[(3-substituted-1H-pyrazol-4 ylmethylidene)amino]-2H-1,2,4-triazole-3-thione (3a–o) and thioglycolic acid. The structures of all the synthesized compounds were confirmed by elemental analysis, spectral techniques like IR, 1 H NMR, and mass spectroscopy. Few compounds exhibited dose-dependent cytotoxic effect in MTT assay in human breast cancer (MCF-7) cells. Apoptotic degradation of DNA due to action of potent thiazolidin-4-ones was analysed by agarose gel electrophoresis and visualized by ethidium bromide staining (comet assay).A concentration-dependent increase in tail length and olive tail moment was observed when treated with thiazolidin-4 ones. In vitro antioxidant studies like DPPH and ABTSfree radical scavenging assays-indicated moderate activity of thiazolidin-4-ones.