Modern biotechnology is one of the most important scientific and technological revolutions in the 21st century, with an increasing and measurable impact on society. Development of biotechnology curriculum has become important to high school bioscience classrooms. This study has monitored high school students in Taiwan on their knowledge of and attitudes towards biotechnology for nearly two decades. Not surprisingly, knowledge of biotechnology of current students has increased significantly (p < 0.001) and most students have learned some definitions and examples of biotechnology. There was a positive correlation between biotechnology knowledge and attitudes toward biotechnology for current students who study Advanced Biology (AB). However, for current students who did not study AB, there was a negative correlation.The attitude results showed that students today expressed less favorable opinions toward agricultural biotechnology (p < 0.001) despite studying AB or not. However, there is no significant difference between students today and 18 years ago in opinions towards medical biotechnology. In addition, current students showed a greater concern involving environmental risks than former students. Interestingly, the high school curriculum did affect students' attitudes toward genetically engineered (GE) plants but not GE animals. Our current study also found that the students' attitude towards GE animals was influenced more by their limited knowledge than by their moral belief. On the basis of findings from this study, we suggest that more materials of emerging animal biotechnology should be included in high school curriculum and recommend that high school teachers and university faculty establish a collaborative framework in the near future.