In the latter half of the past decade, school districts in several large cities, including New York, Chicago, Washington, D.C., and post-Katrina New Orleans, have implemented an urban school decentralization model generally known as "portfolio districts." Others, including those in Denver and Cleveland, are following suit in what appears to be a growing trend. The portfolio strategy has become increasingly prominent in educational policy circles, think tank and philanthropy literature, and education news reporting. As CEO of the Chicago Public Schools, Arne Duncan embraced the portfolio district model. His appointment as U.S. Secretary of Education suggests the Obama administration also supports the approach. The premise of the portfolio strategy is that if superintendents build portfolios of schools that encompass a variety of educational approaches offered by different vendors, then over time school districts will weed out under-performing approaches and vendors; as a result, more children will have more opportunities for academic success. This brief examines the available evidence for the viability of this premise and the proposals that flow from it.