Design, molecular docking, synthesis and evaluation of cytotoxic activity of new compounds I, II, III and IV that have isatin-sulfonamide derivatives. For chemical synthesis, chemical compounds such as sulfonamide, 4-aminoethyl benzoate, isatin and its derivatives were used. For the docking study, the MOE software program version 2015.10 was used. And MTT assay for the prediction of cytotoxic activity. The synthesised compounds demonstrated significant inhibition of carbonic anhydrase XII activity through molecular docking and significant inhibition of cancer cell viability. Compounds II and IV show higher S-scores than acetazolamide. Also, the MTT assay shows IC50 against MCF-7 cells (0.06 µM and 0.105 µM) of compounds II and IV, respectively, when compared with IC50 0.394 µM of acetazolamide. IC50 against Hct116 cells (0.063 µM and 0.114 µM) of compounds II and IV, respectively, when compared with IC50 0.901 µM of acetazolamide. The MTT assay explains that compounds II and IV have better cytotoxic activity compared with acetazolamide. New compounds that were produced showed signs of cytotoxicity and carbonic anhydrase inhibitory qualities.