Graded levels of aflatoxin (0, .625, 1.25, 2.5, 5.0, and 10.0 micrograms/g diet) were incorporated into a broiler-starter ration and fed to chicks from 1 day to 3 weeks of age. The tibias and middle toes were removed, and both bone ash and toe ash were determined. Toe ash significantly (P less than .05) increased at the aflatoxin levels of 2.5 ppm and above, while bone ash significantly (P less than .05) deceased at the same aflatoxin levels (2.5 ppm and above). The increase in toe ash could be partially attributed to a significant (P less than .05) decrease in toe lipid levels at the aflatoxin levels of 2.5 ppm and above. The data indicate that aflatoxin inhibits bone mineralization. The data also show that toe ash does not in all experimental designs reflect bone ash and that data interpreted solely on toe ash determination may not accurately reflect bone mineralization.