Teachers have been shown to frequently avoid addressing biotechnology topics. Aiming to understand the extent to which teachers' scarce engagement in biotechnology teaching is influenced by their beliefs and/or by extrinsic constraints, such as practical limitations, this study evaluates biology teachers' beliefs about biotechnology and biotechnology teaching. The findings of a survey administered to 93 secondary school teachers reveal that, in spite of holding positive beliefs about biotechnology, teachers overestimate the obstacles presented at biotechnology teaching, particularly concerning material and resource limitations. Implications of these findings for teacher training program design are discussed. (Contains 6 tables.)