Teaching nonscience majors topics in biotechnology through case studies is the focus of this research. Our Biotechnology, Environment, and Related Issues module, developed within the Science for All framework, is aimed at elevating the level of students' scientific and technological literacy and their higher order thinking skills. The research goal was to investigate nonscience major students' ability to use various thinking skills in analyzing environmental and moral conflicts presented through case studies in the Biotechnology Module. The research population consisted of about 200 nonscience majors in eight classes of grades 10–12 from heterogeneous communities. We found a significant improvement in students' knowledge and understanding and higher order thinking skills at all academic levels. The scores that low academic level students achieved in the knowledge and understanding category were higher than their high academic level peers' scores. In the higher order thinking skills—question posing, argumentation, and system thinking—a significant difference in favor of the high academic level students was found. The gap that had existed between low and high academic level students narrowed. Most students reported that the biotechnological topics that they had studied were interesting and relevant. Based on these results, we advocate a curriculum that exposes students to scientific controversies through case studies with environmental and moral implications. Our research has shown that this approach is likely to contribute to developing scientific and technological literacy along with higher order thinking skills of nonscience majors. © 2003 Wiley Periodicals, Inc. Sci Ed87:767–793, 2003; Published online in Wiley InterScience ( DOI 10.1002/sce.10081