The effects of Italian and US consumers' risk perceptions, knowledge and awareness of GM foods, and trust in government agencies on willingness to buy GM foods is examined. Results indicated that effects of risk perception of GM foods to human health and the environment are similar between urban consumers in Italy and the United States. However, Italian consumers were found to be more sensitive to the potential risks that GM foods may pose to human health and the environment, relative to the US consumer. In general, Italians were also less likely to purchase GM foods relative to US consumers.