Abstract: The present study investigates the effect of nano-Fe2O3 particles as a micronutrient on the growth of plant seedlings of Mung (Vigna radiate) and Gram (Cicer arietinum) using plant agar method. The laboratory experiment was carried out in the test units comprising of a petri dish and plant agar medium. The plant agar medium used acts as a false soil that supports the seedlings for germination, prevents precipitation of water-insoluble nanoparticles and eliminates the possibility of any nutrients from external sources other than the nano-Fe2O3 particles. Each test unit containing agar media was treated with nano-Fe2O3 particles suspension at different concentrations. The effect of nano-Fe2O3 particle dose-response on root and shoot growth of the seedlings as well as on biomass assay was examined. The results showed that among the various concentrations of nano-Fe2O3 particles studied, a good agronomic value over control was observed only for certain optimum concentration i.e 50 mg/L for mung and 5 mg/L for gram seedlings. Beyond this dose limit the seedling showed retardation in their growth characteristics indicating phytotoxicity.