Principals' implementation of new teacher evaluation policies in a suburban and rural southeastern area of the United States was examined over a five-year period. This study reports findings on two of eleven interview questions examining changes in principals' perceptions over time regarding policy concerns and benefits. Findings indicate while initially overwhelmed, principals eventually managed implementation time challenges and later focused on the benefits of evaluation. Secondly, principals quickly integrated the instructional rubric criteria into classroom observations and professional development work. Third, increasing doubts emerged regarding the inconsistent application of the rubric criteria, the inclusion of student test scores in teacher evaluation, and the calculation of teacher effectiveness ratings. The authors conclude that mandating rigorous evaluation policy will not sufficiently address teacher effectiveness and may complicate principals' instructional leadership. They assert that policy-makers must consider the long-term effects of implementation before substantial teacher evaluation change results.