Engineering has become increasingly prominent in science education, with documents such as Next Generation Science Standards detailing the importance of introducing students at all grade levels to science and engineering practices. Yet, many elementary teachers may lack sufficient engineering content and pedagogical knowledge and report feeling unprepared to teach engineering content and processes. To prepare future elementary teachers to teach engineering, two university faculty members in science and mathematics education designed an engineering unit that was incorporated within an elementary science methods course and supported through an elementary mathematics methods course. This unit focused on the engineering design process as well as connections between the work of scientists and engineers; the processes of science, engineering, and mathematics; and the cycles of engineering design and inquiry. The results of the study provide evidence that the unit had a positive influence on the 27 preservice teacher participants' engineering teaching efficacy, understanding of engineering, and comprehension of the implementation of engineering in the elementary classroom.