A novel series of 2-thiouracil sulfonamide derivatives (3 - 13) were synthesized; and their chemical structures were confirmed by spectral and elemental analyses. All compounds were tested for anti-cancer activity by SRB assay method against Breast (MCF7) and Colon (CaCo-2) cell lines. Most of the tested compounds are active against two cell lines in comparison to 5- fluorouracil. Compound 9 was the most potent against CaCo-2 and MCF7 cell lines (IC50=2.82 and 2.92 µg/mL, respectively). Molecular docking studies for the best active compounds were performed on the active site of c-kit protein tyrosine kinase (PTK). All of the docked compounds exhibited proper fitting on the active site of the c-kit tyrosine kinas with fitness score range from 65.13±0.17 to 69.55±0.39 KJ/mol. The most active compound 9 showed high fitness score (69.55±0.39 KJ/mol).