This study reports on the attitudes towards biotechnology of 905, 15-16 year-old students from 11 Western Australian schools. Students were asked to read 15 statements about biotechnology processes and to draw a line to separate what they considered 'acceptable' statements from those they considered 'unacceptable'. Overall, the students hold a wide range of beliefs about what is an acceptable use of biotechnology. Their attitudes range from those of the 55 (6.0%) students who do not agree with the use of any living organisms in biotechnology to the 125 (14%) students who approve of all the stated uses of biotechnology, with a wide spread in between. Acceptance of the use of organisms in biotechnology decreases as we move from microorganisms (>90%approval) to plants (71-82%) to humans (42-45%) and animals (34-40%). The attitudes of 99 students who recently studied biotechnology and have a good understanding of the processes and issues were similar in percentage and spread to those who were less informed.