This study examined the development of prospective teachers' (PTs) understanding of productive struggle using video episodes which PTs analyzed through the lens of professional teacher noticing. Our qualitative study included 66 PTs in four sections of a semester-long mathematics content course for prospective elementary and middle school teachers that focused on numbers and operations. The goal was to give PTs opportunities to observe students struggling with the course content the PTs were studying and to enact their specialized content knowledge and pedagogical knowledge for teaching simultaneously. Findings suggest that the PTs develop the ability to attend to and interpret the mathematics underlying the student struggles through video analyses. They also begin to identify teaching strategies and practices that appear potentially useful for supporting productive struggle. The use of a productive struggle framework helped the PTs develop a language for discussing productive struggle. Findings also suggest that PTs who had very little knowledge of productive struggle became more aware of what it looks like in practice, discuss ways to support students' struggle and suggest its potential value in supporting students' understanding of mathematics. One implication for this study is to carefully weave opportunities to develop teaching practices such as support of productive struggle into the content course for teaching. The PTs may better bridge the stance between being a student and becoming a teacher in what productive struggle looks like in learning mathematics.