Induction of micronuclei and chromosomal aberrations produced by whole body exposure of r-radiation (1.5-3.0 Gy) in mice was found to be significantly inhibited by oral administration of natural antioxidants, curcumin (400 micro moles), ellagic acid (200 micro moles) and bixin (200 micro moles) per kilogram body weight. These antioxidants induced inhibition of micronucleated polychromatic and normochromatic erythrocytes, was comparable with alpha-tocopherol (200 micro moles) administration. Curcumin and ellagic acid were also found to significantly reduce the number of bone marrow cells with chromosomal aberrations and chromosomal fragments as effectively as alpha-tocopherol. Moreover, administration of antioxidants inhibited the DNA strand breaks produced in rat lymphocytes upon radiation as seen from the DNA unwinding studies. These results indicated that antioxidant curcumin, ellagic acid and bixin provide protection against chromosome damage produced by radiation.