Teachers are not adequately trained to analyze the instructional needs of their students through the use of student performance data. The purpose of this case study was to explore how one elementary school in the northeastern United States used collaborative inquiry to perform this function. The theory of transformational leadership served as the underpinning for this study. The research questions central to this study focused on how 6 third grade teachers and their principal used collaborative inquiry to access and analyze student performance data, discuss instructional direction, and plan for instruction accordingly. This study also examined the leadership practices employed by the principal that supported this process. Data were collected through interviews of 6 teachers and their principal, observations of collaborative inquiry meetings, and a review of unobtrusive documents related to the collaborative inquiry process. These data were examined using a typological analysis and triangulated to validate emerging themes related to each research question. This study concluded that the use of collaborative inquiry was beneficial for analyzing the instructional needs of students via state and benchmark assessment data. Furthermore, transformational leadership strategies employed by the principal helped to facilitate professional discourse and collaborative planning among the teachers. Findings from this study could lead to positive social change. This study offers educators one strategy for analyzing student performance data to guide instructional decisions and potentially increase the academic achievement of students.