The aqueous extract of flowers of I. coccinea was evaluated for its cytotoxic and mutagenic effects on the meristematic cells of onion root tip. The percentage of abnormalities was found to increase with the increase in the concentration of the extract from 20 to 60 mg/ml. With 80 mg/ml completed arrest or total inhibition of cell division was observed. The major abnormalities were unprinted chromosomes at metaphase. Stickiness and clumping of chromosomes were induced by higher concentrations of the extract. Sticky anaphase bridges and formation of micronuclei were induced at the highest concentration (80mg/ml) tried. The significance of these abnormalities is discussed in detail. The results point to the potential use of the aqueous extract of flowers of I. coccinea in the chemotherapy of cancer.