Using data from the 2003-04 Schools and Staffing Survey, the authors studied how various aspects of teacher preparation affect the retention of new teachers--specifically mathematics and science teachers. They found that the preparation of new mathematics and science teachers differs from that of other new teachers in various respects, but factors that had to do with pedagogical training (amount of practice teaching, courses in educational methods and child psychology, and so on) were the only ones that positively affected teacher retention. This finding is a concern for mathematics and science education, write the authors, because mathematics and science teachers tend to receive significantly less pedagogical training than other teachers, and their attrition rates after the first year of teaching are higher. (Contains 2 figures and 2 endnotes.)