This study addresses the question: Do the kinds and amounts of pre-service education and preparation that beginning teachers receive before they start teaching have any impact on whether they leave teaching? Authors Richard Ingersoll, Lisa Merrill, and Henry May examine a wide range of measures of teachers' subject-matter education and pedagogical preparation. They compare different fields of teaching, with a particular focus on mathematics and science, using data from the National Center for Education Statistics' nationally representative 2003-04 Schools and Staffing Survey and its supplement, the 2004-05 Teacher Follow-up Survey. The analyses show that beginning teachers widely varied in the pre-service education and preparation they received. In general, mathematics teachers and, especially, science teachers tended to have more subject-matter content education and more graduate-level education, and to have less pedagogical and methodological preparation than other teachers. The analyses also show that, after controlling for the background characteristics of teachers and their schools, some aspects of the education and preparation that beginning teachers received were significantly associated with their attrition, while others were not. Specifically, the type of college, degree, entry route or certificate mattered little. What did matter was the substance and content of new teachers' pedagogical preparation. Those with more training in teaching methods and pedagogy -- especially practice teaching, observation of other classroom teaching and feedback on their own teaching -- were far less likely to leave teaching after their first year on the job.