In this mixed-method research study, data from public school personnel were used to determine the professional preparation of teachers through the National Board Certification process. The major goals of the study were to (a) analyze the perceptions of public school principals on the effectiveness of National Board certified teachers, (b) analyze the perceptions of teachers on the effectiveness of National Board certified teachers, and (c) determine whether differences exist in their perceptions based on gender, ethnicity, school role, and school level. The results from the mixed-method analysis showed that public school personnel's perceptions on the effectiveness of National Board certified teachers varied. (Contains 6 tables.)