The disproportionate representation of students from culturally and linguistically diverse backgrounds in special education programs is a complex issue that has long troubled practitioners, educational leaders, and researchers. This article reports on a mixed-method collaborative case analysis that examined local patterns of disproportionality in an urban school district and the district's systemic transformation effort to address disproportionality. In a close collaboration with the district's special education leadership team, we utilized student-level quantitative data from 2006 through 2010 to examine temporal patterns of disproportionality along with qualitative data on the leadership team's perceptions and actions. Our analyses showed that risk of overidentification was greatest for African American, American Indian, low-income, and male students. The study illustrates a method of collaborative analysis and the importance of such analyses for understanding and addressing variously localized patterns of disproportionality. The findings contribute to the literature on disproportionality and inform systemic change efforts in diverse sociocultural contexts of urban school districts.