This study investigates how members of anti-GM campaign groups and environment groups perceive the risks and benefits of genetically modified (GM) technology in food and agriculture. The study targeted these groups as the most risk-averse sector of society when considering GM technology. Survey respondents were asked to rank the current and future risks and benefits of GM and to rank GM risks against other health risks. Respondents appear to be unconvinced by the claims that future GM technologies will provide additional consumer (or environmental) benefit, since perceived future risks were ranked more highly than future benefits. Results support the claim that there is an inverse relationship between perceived risk and perceived benefit. Results also suggest that among the respondents there are differences of opinion regarding the degree of risk to health posed by the technology. Women and people living in rural areas, on average, ranked risks more highly than men and people living in urban areas. This study serves to fill a void in the understanding of the perceptions of anti-GM campaigners.