The purpose of this study was to determine the knowledge levels of popular biotechnological issues of Turkish science and elementary teacher candidates. A questionnaire was administered during 2006-2007 school term to 336 students pursuing their education in the departments of science and elementary education in two Turkish universities. The questionnaire covers six biotechnological issues such as biotechnology, agrobiotechnology, human health and pharmacy, environment and biotechnology, and food production with biotechnology. Results revealed that whereas science and elementary teacher candidates had an approximate consistent knowledge of describing biotechnology and human health/pharmacy that almost all students had an inadequate knowledge about other biotechnological issues. The mean of the knowledge levels of science teacher candidates was significantly higher than that of elementary teacher candidates at the popular biotechnological issues. On the other hand, there was no significant mean difference between female and male science and elementary teacher candidates' knowledge levels related to biotechnology. In the result, the elementary and science education programs should be regulated to put extra effort to increase teacher candidates' awareness of biotechnological topics and issues in Turkey since one of the important future technologies seems to be biotechnology. (Contains 7 tables and 1 footnote.)