The frequencies of chromosomal aberrations in Giemsa-banded preparations obtained from peripheral blood cultures of 5 kwashiorkor, 3 marasmic and 2 marasmic-kwashiorkor patients were investigated. Analysis of 1120 metaphases from these patients revealed an aberration rate of 5.80 per cent as against a frequency of 1.66 per cent seen in control children. However, no particular chromosome or chromosome group seems to be more affected in malnourished children. Furthermore, malnourished children with associated infections were observed to exhibit more number aberrations than those without infections. These observations thus, support the suggestion that malnourished children exhibit increased frequencies of chromosomal damage.