Glyphosate tolerant (GT) soybeans appear to be popular among many Ontario farmers. For example, Statistics Canada reports that 23% of the 2001 soybean acreage was planted to GT varieties, up from 18% in 2000. However,  the environmental impact of GT seeds is perceived as controversial in the minds of some members of the public.  This manifests itself in the form of public action on behalf of some activist groups, and a demand for products not containing GT soybeans. The apparent contradiction between producer preferences and public attitudes lies in a general lack of knowledge surrounding the environmental impact of GT soybeans. In this regard, the specific impact  of GT soybeans in Ontario is unknown.Two recent studies investigated the impacts of GT technology on soybean production in the United States. Similar studies have not been conducted that measure the agronomic, economic and environmental impacts of GT soybean technology in Canada. Based on the forgoing, an analogous study measuring these impacts in Ontario agriculture is warranted.  The purpose of this study is to assess the agronomic, economic and environmental impacts of Glyphosate tolerant soybeans in Ontario by conducting similar analyses as Hin et al. and ASA, but using Ontario data. As such, the study will provide a measurement of the agronomic, economic and environmental impacts of GT soybean technology.