Systemic infection of maize incited by Peronosclerospora sorghi results in the chlorosis of leaves, reduction in leaf area index and also changes in the chemical composition of leaves. Infected leaves showed a reduction in the quantity of total chlorophyll, chlorophyll a and b and sugars but the quantity of crude protein and crude fibre were not significantly altered. Among the micronutrients, increased quantity of Fe and Cu but reduced quantity of Mn and Zn were recorded in the infected leaves.