The objective of our study was to investigate young people's attitudes towards modern genetics and biotechnology. Quantitative and qualitative studies were conducted among high school students in Rio de Janeiro. These included a survey of students in nine public and private schools as well as focus groups for a complementary analysis of their attitudes and perceptions with respect to these subjects. We observed that, in general, students are relatively well informed about some of the main issues related to the applications of genetics. In their assessment of the utility, the potential risks, and the need for encouragement of the different techniques used in genetic manipulation, they were able to make clear distinctions between the different purposes of each technique. Most students believed that transgenic food could be useful and that it should be encouraged, but they were also aware that there were risks involved. Furthermore, the students were strongly supportive of the labeling of transgenic food.