Zinc concentration was measured in hair samples from 57 infants (27 boys and 30 girls) aged 7 to 24 months. Twenty-eight infants were considered eutrophic and 29 presented chronic and severe malnutrition. 2. Hair segments less than 3-cm long were cut close to the scalp in the occipital area and washed in deionized water and acetone. Zinc levels were measured by neutron-activation. 3. Hair zinc concentration decreased with age in both eutrophic and malnourished infants from 160 micrograms/g at 7 months to 90 micrograms/g at 24 months. 4. No statistically significant difference in hair zinc concentration was detected between eutrophic and malnourished infants (148 +/- 60 vs 128 +/- 57 micrograms/g hair, mean +/- SD) or between sexes.