Our education system aims to equip young people with the knowledge, problem-solving skills and values to cope with an increasingly technological society. The aim of this study was to determine the effect of biotechnology education on adolescents' understanding and attitudes about processes associated with biotechnology. Data were drawn from teacher and student interviews and surveys in the context of innovative Year 10 biotechnology courses conducted in three Western Australian high schools. The results indicate that after completing a biotechnology course students' understanding increased but their attitudes remained constant with the exception of their views about human uses of gene technology. The findings of this study have ramifications for the design and implementation of biotechnology education courses in high schools. (Contains 3 tables and 1 figure.)