There is an enormous gap between scientific production and scientific education in Genetics and Bio-technology concerning stem cells, transgenics, genetically engineered medicines and so on. In order to investigate the knowledge and the perception of these concepts among teenagers, a total of 334 surveys were distributed to high school students in one private and two state schools in theRio de Janeirostate,Brazil. Interviews were also used as a qualitative tool to assess the validity of the data obtained in the surveys. Students reported clear ideas about transgenics, but not about genetic engineering of recombinant medication or genomics. The results suggest that when issues are discussed,instead of being explained, they are better assimilated by students, and that association of information in the press with school classes may help to spread scientific concepts.