A study conducted to findout the allergenic effect of air borne pollens of various wasteland weeds on human beings, by performing skin patch test revealed that out of 11 species studied, the most prominent allergenic pollen grains were those of Abitulon indicum and Croton bonplandianum which caused allergenicity to the extent of 19 and 17 per cent, respectively. Cynodon dactylon, Dicanthium annulatum and Eupatorium odoratum  showed  high allergenic response in the individuals of the weight group between 41-50 kg. Males were less allergenic to Lantana camara, Tridax procumbens and Amaranthus spinosus. However, it was high in Croton bonplandianum, Cassia hirsuta and Abitulon indicum. The individuals who were not susceptible to parthenium or any other weeds showed high % of allergenicity to all the weed species studied. In general, the incidence of allergenicity was less in Lantana camara, Tridax procumbens, Bidens pilosa and Cassia hirsuta. The pollen grains although found in the atmosphere, the weeds exhibited less allergenicity, hence these can be considered as less prolific to human health. Considering eco-friendly nature, these weeds can safely be conserved in the ecosystem to maintain the ecological balance.