Biotech crops have now been grown commercially on a substantial global scale since 1996. This article examines the production effects of the technology and impacts on cereal and oilseed markets through the use of agricultural commodity models. It analyses the impacts on global production, consumption, trade, and prices in the soybean, canola, and corn sectors. The analysis suggests that world prices of corn, soybeans, and canola would probably be, respectively, 5.8%, 9.6%, and 3.8% higher, on average, than 2007 baseline levels if this technology was no longer available to farmers. Prices of key derivatives of soybeans (meal and oil) would also be between 5% and 9% higher, with rapeseed meal and oil prices being about 4% higher than baseline levels. World prices of related cereals and oilseeds would also be expected to be higher by 3% to 4%.