This case study investigated the implementation of an inquiry-based curricular unit that was designed to promote student discourse and debate on aspects related to the nature of science, using a socioscientific issue of genetically modified foods. Two high school science classrooms participated in the study that took place over seven consecutive 1.5-h period blocks. The researchers utilized qualitative procedures to analyze students' views on the nature of science as expressed through their answers to online and interview questions, and to examine features of argumentation and discourse in the final classroom debate. The students' answers to questions related to the nature of science reflected conceptions of the tentative, creative, subjective, and social aspects of science. Yet aspects of the nature of science did not enter into the debate discussions. Instead students utilized more factual-based content of the evidence that ultimately led into numerous instances of fallacious reasoning and personal attacks. These findings suggest that perhaps a socioscientific issues approach to exploring aspects of the nature of science should be designed so that students are moved beyond developing their nature of science conceptions to applying those conceptions within a decision-making context. (Contains 4 tables and 1 figure.)