The foliar and cambial responses of Prosopis cineraria to five different coal-smoke regimes in Delhi, India, were studied using the monthly collections of leaves and cambial blocks as well as the data on SO 2 , NO 2 and particulate concentrations from each of the five study sites. Coal-smoke inhibited pigment concentration, NR activity and sugar content and promoted stomatal index and the nitrate and sulfur contents. Stomatal conductance was low, leading to a drop in the net photosynthetic rate. Cambial activity started quite late and the annual increment of wood was reduced despite a prolonged active phase, possibly due to a distinctly retarded rate of cambial cell division. Vessel proportion in the wood increased but the size of vessel elements and fibers decreased. Such studies may help in identifying trees suitable for cultivation in the pollutionaffected areas.