The Youth Development Initiative (YDI) was a 5-year, $4.3 million dollar project to strengthen the management and organizational capacities of nonprofit youth-serving organizations so they could better meet expanding demands for service in their communities. Ten youth-serving organizations in Fresno, California, and 10 in Los Angeles participated in the initiative. YDI worked at improving the agencies' operations and building their infrastructure in the following management areas: (1) administration and finance; (2) facilities management; (3) fund development; (4) governance (board and executive leadership); (5) staff development and training; (6) information and technology support; (7) legal (personnel and liability management; and (8) planning and evaluation. Local and cross-site evaluations were conducted to identify organizations' accomplishments, strengths, and challenges. During the YDI, the mean annual budgets of the 20 participating youth-serving agencies at the end of the grant period increased from $570,000 to $875,000 and their average full-time staff positions increased from 9 to 17. The total number of youths served by the Fresno agencies tripled and the total served by the Los Angeles agencies increased by 20%. The organizations diversified their funding sources and increased their success rate in receiving grants by 68%. The YDI also had positive impacts on intermediary organizations, technical assistance providers, and evaluators. (MN)