This study investigates the relationship between the academic background of teachers of advanced placement (AP) classes and the scores of their students on the nationally administered advance placement examinations. The effect of teacher characteristics on the exam scores was found to be significant. Classes which did poorly on the exams were more likely to have had teachers with weak backgrounds. Conversely, classes in which the average exam score was 4+ (out of 5) were far more likely to have had teachers with strong backgrounds. In addition, classes in which teachers were inexperienced in teaching at the AP level tended to do less well while classes of teachers who had more than 10 years of experience teaching advanced placement classes did much better than average. Regression analysis showed the interaction of the ranking of the teacher's undergraduate university and the teacher's undergraduate grade-point average in the AP subject to have a significant effect on student score. (Author)