Across education sectors in the United States, the drive to close chronic achievement gaps has piqued interest in school leadership as a cost-effective lever for implementing standards-based reforms. Similarly, the national consensus around early childhood education (ECE) has focused new attention on directors and supervisors as instructional leaders and critical collaborators in building center-based organizational capacity for continuous quality improvement. Little research, however, has examined the capacity of leaders in urban, community-based ECE centers to engage their staff in more ambitious, multi-modal job-embedded professional development (JEPD), the approach to PD gaining prevalence in K-12 educational settings. The present study reports findings from a 3-year development evaluation of a comprehensive ECE Professional Development Initiative (ECE PDI) in a large, Midwest urban center, funded through the federal Investing in Innovation (i3) grant program. (author abstract)