Science teachers have been urged to use emerging technologies, such as robots, in ways that empower K-12 students as active participants responsible for their learning and knowledge development within the scientific domain. And yet, little is known about whether the use of robots effectively supports students' epistemic agency in science learning. The purpose of this qualitative case study was to investigate to what extent elementary preservice teachers use educational robots in ways that promote epistemic agency in science lessons. Seven data sources were gathered for this study: individual reflections about lesson planning and lesson design, team reflection about teaching with robots, robotics-enhanced science lessons, posters, video-recorded presentations about designed lessons, and participant interview. A framework of epistemic practices for science inquiry was adopted to analyze the data followed by qualitative thematic analysis. Results indicate that the use of robots in science lessons promotes content assimilation rather than self-driven inquiry, robot movement rather than evidence drives science explanations, science activities with robots are situated in a social vacuum, and robot assembly and programming are underutilized in the lessons. Implications for preservice science teacher education and future research are discussed.