The purpose of this study was to determine the knowledge level of popular biotechnological issues of prospective Turkish science teachers. A questionnaire was administered during 2005-2006 academic year to 194 students in the Department of Science Education of a university in Turkey. The questionnaire covered six biotechnological issues such as biotechnology, agrobiotechnology, human health and pharmacy, environment and biotechnology, and food production with biotechnology. Results showed that whereas department of science education students had an approximate consistent knowledge of describing biotechnology and human health/pharmacy that almost all students had an inadequate knowledge about other biotechnological issues. Finally, the results were compared with other studies in the world. (Contains 6 tables.)