An investigation was initiated to examine the effects of nanoscale titanium dioxide particles on plant growth and development. In view of the widespread cultivation of canola in Iran and in other parts of the globe and in view of the potential influence of titanium on its growth, this plant was chosen as the model system. Canola seeds were separately treated with different concentrations of nanoscale titanium dioxide (10, 100, 1000, 1200, 1500, 1700 and 2000 mg l-1 and the effect this treatment was studied on seed germination and seedling vigor. Treatment of nanoscale TiO2(20 nm mean particle size) at 2000 mg l-1 concentration promoted both seed germination and seedling vigor . The lowest and the highest germination rate were obtained in 1500 and 2000 mg l-1 treatments, respectively. Higher concentrations of nanoscale TiO2 (1200 and 1500 mg l-1) showed large radicle and plumule growth of seedling compared to other concentrations and control. The inhibitory effect with lower nanoparticle concentration reveals the need for judicious usage of these particles in such applications. This is the first report on the effect of nanoscale particles on canola growth.