In the present study aqueous extract of medicinal plants viz., Amaranthus spinosus,Chenopodium album, Catharanthus roseus, Solanum nigrum and Ocimum sanctum were investigated for their nematicidal activity against second stage juvenile of Meloidogyne incognita by in vitro technique. Aqueous extract of all plant roots exhibited nematicidal activity. LC50 values calculated as 1024 ppm for C. roseus, 1867 ppm for S. nigrum, 1968 ppm for A. spinosus, 3428 ppm for C. album and 962 ppm for O. sanctum. LC50 values showed that out of these extracts O. sanctum found to be the most effective. In vivo experiment was conducted to study the effect of root extract of O. sanctum on M. incognita infecting French bean. Different concentrations viz., 10000 ppm (S), 5000 ppm ( S/2), 2500 ppm (S/4), 1250 ppm(S/8), 625 ppm (S/16) and 312.5 ppm (S/32) of aqueous extract of O. sanctum roots was applied by seed soaking and foliar spray methods.