In this article we present results of a comprehensive review of principal leadership assessment practices in the United States. Our analyses of both the general content and the usage of 65 instruments, 56 at the district level and 9 at the state level, provided an in-depth look at what and how districts and states evaluate principals. Using the learning-centered leadership framework, we focused on identifying the congruence (or lack thereof) between documented assessment practices and the research-based criteria for effective leadership that are associated with improved school performance. Using an iterative and deductive process for instrument content analysis, we found that states and districts focused on a variety of performance areas (e.g., management, external environment, or personal traits) when evaluating their principals, with different formats at various levels of specificity. We also found very limited coverage of leadership behaviors that ensure rigorous curriculum and quality instruction, which are linked with schoolwide improvement for the ultimate purpose of enhanced student learning. In seeking information on how principals are evaluated, we found that in most cases, the practices of leadership assessment lacked justification and documentation in terms of the utility, psychometric properties, and accuracy of the instruments. (Contains 4 figures, 2 tables and 1 note.)