The vast majority of teachers who engage in the process of National Board certification describe it as the best professional development they have ever experienced - even when they do not achieve the certification. Learning leverage, an interactive dynamic characterized by rigor, reward, and risk, is what makes the certification process such a powerful learning experience for teachers. The leverage of National Board candidacy is an uncomfortable yet positive pressure that usually leads to substantial teacher learning. It occurs naturally among National Board candidates, but varies from individual to individual. This article explores research on teacher learning as it occurs through the process of National Board candidacy, then introduces and illustrates the concept of learning leverage based on the experiences of three teachers who pursued NBPTS certification during the 2004-2005 school year. By understanding learning leverage as it occurs through the process of National Board candidacy, teachers considering the pursuit of NBPTS certification can approach the process better prepared for a successful certification experience. (Contains 5 figures.)