For students, quality teaching means the difference between a bright or potentially dim future. School principals face several challenges that work against recommending contract non-renewal for incompetent teachers. This study investigates the reasons that school principals recommend contract non-renewal of probationary teachers. Targeted elementary, middle, and high school principals in the Southeastern United States participated in this study. Completing a mailed survey, school principals identified ethical violations and teacher misconduct as the most likely reason they would pursue teacher contract non-renewal. Teacher incompetence was identified as the second most likely reason principals would recommend a contract non-renewal. While there were no statistically significant responses by the various demographic groups of principals, there were several differences in their selections. As an example, suburban principals seemed less concerned with classroom management than other school principals. School principal responses were classified according to teacher knowledge, skill, or disposition. The study's principals identified dispositions as particularly related to the likelihood of a contract non-renewal. The study offers several suggestions for improving teaching and leadership practice. Additionally, future areas for discussion and investigation benefitting both teachers and principals are offered. (Contains 3 tables.)