In this master thesis, we present results of a study on the attitudes toward and interests in genetically modified organisms (GMOs) among high-school students. First and secondyear students participated in the study by filling in a questionnaire twice - before and after the classroom discussion on GMOs. The questionnaire consisted of questions on knowledge and sources of information on GMOs and twenty-five statements assessing the respondents' interests and attitudes towards GMOs. We calculated the mean value of the total score for attitude 2.86 (SD = 0.439), which was statistically significantly more negative than the neutral opinion. Further on, we compared this result with the mean value of the overall assessment of the attitude score after students have been informed about GMOs. We found that the latter was statistically significantly more positive. Using the mixed design ANOVA method, we found that teachers do not change their students’ attitudes. Our results show that the high-school students were interested in GMOs even before they have studied GMOs in the classroom. However, their interest has remained statistically significant even after that. To conclude, the education of students on GMOs influences the students' attitudes, but does not change their interest in GMOs.