The effects of aqueous leaf extracts of Tectona grandis L. and Mikania micrantha L. on germination and growth of Zea mays L. (maize) and Oryza sativa L. (paddy) were investigated during 2009-2010. The extracts suppressed the germination of paddy to an extent of 10-30% under high extract concentration and 40-50% suppression in maize under similar concentration. The growth of root and shoot of both the test crops also got suppressed under high extract concentration. Similar was also the case with M. micrantha where germination of paddy was suppressed to an extent of 10-35% and 45-65% suppression in maize under high extract concentrations. There is a slight decrease in 10% concentration in case of both the test crops. As the concentration increased from 30-100% the aqueous leaf extract of M. micrantha has detrimental effect on the root and shoot growth of both the test crops.