In this essay, we describe some challenges that mathematics teacher educators may face when teaching content courses for future elementary and middle school teachers. We summarize research that suggests students in content courses may have fixed mindsets, unproductive beliefs, and mathematics anxiety that can interfere with their ability to learn mathematics content. We suggest possible interventions to address these affective issues, including student-centered instruction, valuing mistakes, process praise, self-directed learning, and activities that inspire student reflection related to his or her own mathematical understandings.