Integrated curricula have become a major educational focus in Korea. Policy changes began in 2009 when the Korea Ministry of Education, Science, and Technology announced a new curriculum incorporating Science, Technology, Engineering, Arts, and Mathematics (STEAM). Various stages of educational reform have occurred since that time. This study represents the first opportunity for readers of English-language journals to learn about these changes. The aims of the current study are to demonstrate the potential for engaging elementary school pre-service teachers in development of STEAM lesson plans within a science methods course and to elucidate the challenges in this instructional approach. Participants were 119 elementary pre-service teachers in their third year of study at a national university in Korea. Results show that developing STEAM lesson plans had a positive influence on elementary pre-service teachers' attitudes toward STEAM. Specifically, we found significant improvement on a pre-post survey for participants' awareness, perceived ability, value, and commitment for STEAM. Secondly, qualitative coding analysis of open-ended surveys revealed pre-service teachers' views of the potential benefits and challenges of developing STEAM lesson plans. Finally, we provide a rubric for evaluating pre-service teachers' STEAM lesson plans, based on our experience with teaching this skill within a science methods course.