Growing use of oxide nanoparticles has driven their access to the natural environment, including biological interactions within the ecosystem, despite a lack of knowledge about their genotoxic potential on exposed plant tissue. In this study, seeds of broad beans (Vicia faba L.), one of the major carbohydrate food sources as well as an ecotoxicological model plant, were treated with three concentrations (25, 50 and 75 mg/L) of two different types of nanoscale materials (n–), n–SiO_2 and n–TiO_2, to assess their safe use. Seeds were soaked in n–SiO_2 and n–TiO_2 each for 24 h, then germinated in peat moss for two weeks. DNA was isolated from leaves for RAPD (Random Amplified Polymorphic DNA) profile analyses. Results revealed a concentration dependent genotoxic effect for n–SiO_2 (however it seems to maintain genetic material stability) and high genotoxic effect for n–TiO_2.