The novel 1-(1-benzoylindoline-5-sulfonyl)-4-phenyl-4,5-dihydroimidazolones 2 shows highly potent and broad cytotoxicities. Their cytotoxicities against human lung carcinoma A549, human chronic myelogenous leukemia K562, and human ovarian adenocarcinoma SK-OV-3 are compatible with doxorubicin. Compound 2p (1-[(4-aminobenzoyl)indoline-5-sulfonyl])-4-phenyl-4,5-dihydroimidazolone) exhibits a cytotoxicity that is far more potent than doxorubicin and also exhibits highly effective antitumour activities against murine (3LL, Colon 26) and human xenograft (NCI-H23, SW620) tumor models.