Cancer represents one of the main causes of mortality in developed countries. In particular, the overall survival of patients with renal cell carcinoma (RCC) remains poor and the available cytostatic agents are insufficient. Therefore, there is an urgent requirement to identify more effective and safer anticancer drugs. Recently, the evaluation of antitumor activity appeared to be promising for thiazolidinone derivatives. The present study presents the synthesis and the cytotoxicity assays of 1,3‑thiazolidin‑4‑ones. The newly synthesized substances were screened in vitro against selected cancer human renal cell adenocarcinoma cells (769‑P), human hepatoblastoma‑derived cells (HepG2) and normal green monkey kidney cells (GMK) as a reference cell line. N‑[2‑(4‑methylphenyl)‑4‑oxo‑1,3‑thiazolidin‑3‑yl]acetamide and N‑[2‑(4‑methylphenyl)‑4‑oxo‑1,3‑thiazolidin‑3‑yl]benzamide displayed significant antiproliferative activity towards 769‑P. To elucidate the mechanisms of the cytotoxic actions, additional studies on the cell cycle and apoptosis were performed. The aforementioned compounds were responsible for G1 cell cycle arrest and the decrease in cell distribution in the G2 phase in a dose‑dependent manner, which prevents mitotic divisions of the 769‑P cells. In addition, these novel 2,3‑disubstituted 1,3‑thiazolidin‑4‑ones slightly induced apoptosis in 769‑P in a dose‑dependent manner. It was hypothesized that the 4‑methylphenyl group at position 2 of the thiazolidin‑4‑one scaffold may be regarded as a promising moiety for further development of this group of compounds. Therefore, benzamide moiety appeared to be crucial for triggering cells to apoptotic cell death.