This study investigated the impact of analyzing student work on preservice teachers' knowledge and beliefs about mathematics teaching. Forty-two prospective teachers participated. Data were collected using established instruments from the Integrating Mathematics and Pedagogy (IMAP) project and from the Learning Mathematics for Teaching (LMT) project. Results are shared along with the protocol used to guide the treatment. Findings show that preservice teachers who learn through the analysis of student work experienced a significant impact on their beliefs regarding how mathematics should be taught. Findings also show student work analyses did not diminish content knowledge development. Implications for undergraduate mathematics education courses are presented.