Commercial cultivation of switchgrass in Ontario is limited mainly due to inadequate market opportunities. However, recent developments in bioproducts identify switchgrass as a promising biomass crop for bioenergy and biomaterials applications. At present assessment of environmental impact of growing switchgrass in Ontario is lacking. Therefore, this study was conducted to evaluate the energy use and environmental impacts of switchgrass biomass production in Ontario through life cycle assessment. Cradle to farm gate life cycle assessment was conducted following the ISO 14040/14044 guidelines. Life cycle inventory data were collected from farmers, experts and available literature. Life cycle impact assessment was conducted for energy use and environmental impact using the SimaPro software. Life cycle processes related to fertilization, harvesting and soil N emission were identified as major hot spots for energy and environmental impacts. Improving efficiency of energy, inputs and biomass yield will reduce the environmental burden associated with growing switchgrass in Ontario. / OMAFRA- UofG Highly Qualified schlorship programme and OMAFRA- UofG Partnership bioeconomy industrial uses reaserch theme project funding.