Robotics is conducive to STEM learning. However, teachers are not prepared to integrate robotics into teaching STEM. Additionally, technology in general is used to transmit knowledge to support student learning from technology. To achieve meaningful learning outcomes, students need to use technology as a cognitive tool and learn with technology. This study examined how and why elementary education pre-service teachers integrate robotics into their lesson design. We analyzed pre-service teachers' lesson plans and conducted interviews. Our findings suggested that, in general, pre-service teachers designed lesson plans for student learning with technology. Pre-service teachers reported a lack of STEM knowledge and knowledge on integrating robotics into their lessons. Their classroom experience as students seemed to have affected their design.