The purpose of this study is to examine the impact of a robotics-based intervention on elementary-aged students' interest in STEM subjects and careers. Participants were thirty-seven second and third grade students from two classrooms at an elementary school in the Southeastern United States. Action research was used to examine a multifaceted, constructionist, and robotics-based intervention that included weekly WeDo Lego Robotics building and coding sessions facilitated by trained STEM-speaking adults to scaffold students' interest in STEM subjects and careers, a classroom STEM learning center, and student participation in a robotics showcase. The intervention was found to have a positive impact on students' interest in STEM subjects and careers. This study provides practitioners with a multifaceted robotics-based intervention that can be integrated into elementary classrooms in as little as two hours per week for sixteen weeks and result in student acquisition of positive attitudes toward STEM subjects and careers.