A mediated field experience (MFE) mathematics methods course increased both pre-service elementary teachers' (PSTs) self-efficacy for teaching mathematics and mathematical dispositions. The semester-long MFE with significant, structured teaching experiences was conducted onsite at an elementary school. Quantitative, pre- and post-surveys of mathematics teaching efficacy revealed statistically significant increases over the semester. A qualitative analysis of PSTs as sophomores and seniors further explored and supported this increase in PSTs' self-efficacy for teaching mathematics. Qualitative data also revealed interesting changes in mathematical dispositions and a shift in PSTs from a self-as-student perspective to a self-as-teacher focus.