Flavonoids compounds such as kaempferol (1), kaempferol-3-O-β-D-glucopyranoside or astragalin (2) and kaempferol-3-O-α-L-rhamnoside or afzelin (3) have been isolated from the fresh leaves of Kalanchoe tomentosa (Crassulaceae). The chemical structure of isolated compounds 1-3 were identified by spectroscopic evidences and comparison with those compound previously reported. Compounds 1-3 showed cytotoxic activity against P-388 murine leukimia cells with IC₅₀ values of 51.8, > 100 and 3.32 µg/mL, respectively.