As anyone in a partnership--a marriage, a business, a professional relationship--will attest, it takes hard work and energy, time and persistence, and reciprocal commitment to make a partnership successful. Writing from the perspective of an external partner, the authors explore lessons learned from eight years of working with public school districts. As an organization committed to large-scale instructional improvement, the Connecticut Center for School Change partners with six geographically and demographically diverse school districts across the state ranging in size from 2,200 to 15,000 students. Their work is informed by the concept that "system success equals student success." The center works in partnership with district leaders to develop leadership, build organizational capacity, and enhance knowledge. Unlike many of the relationships--programmatic, commercial transactions--that districts have with external partners for professional development, their partnerships are systemic, long-term, mutually respectful relationships grounded in Learning Forward's Standards for Staff Development (NSDC, 2001).