This report is a comparative study of the in vitro cell-growth inhibitory activity of six new trifluoromethylquinoline derivatives on human promyelocytic leukemic cells and the evaluation of their DNA binding characteristics. 2,8-Bis(trifluoromethyl)quinoline-4-(N(4)-ethyl-5-nitroimidazolo)methylene ketone shows the highest cell-growth inhibitory activity with IC(50) of 10+/-2.5 microM, causes extensive changes in the morphology of the HL-60 cells and appears to induce apoptosis. The other compounds are only moderately growth-inhibitory, while 8-trifluoromethylquinoline-4-(N(4)-ethyl-5-nitroimidazolo)methylene ketone is actually stimulatory to cell growth. Except for the latter, the cell growth inhibitory activity of these compounds appears to be due their ability to bind to and intercalate DNA.