The efficiency and productivity of Colombia’s urban system will be a key determinant in the ability of the country to transition from a middle to a higher income economy. Economic growth is strongly driven by commodities in Colombia and other Latin American countries. However, the contribution of urban activities to urban growth is non-negligible when all urban activities are added. Strengthening the roles of cities may contribute to mitigating the risks inherent to commodity intensive economies and can support a stronger resource-based manufacturing economic structure and more knowledge intensive industries. In addition, a well functioning urban system is important for quality of life in a country with a highly urban population: almost 80 percent of Colombians live in urban areas, and urbanization is correlated with poverty reduction and improved access to basic services. The Colombia Urbanization Review: Amplifying the Gains from the Urban Transition aims to provide diagnostic tools to inform policy dialogue and investment priorities on urbanization by operationalizing the framework for urban policy developed in the 2009 World Development Report, Reshaping Economic Geography and the Bank’s new Urban and Local Government Strategy, System of Cities: Harnessing Urbanization for Growth and Poverty Reduction. The review was implemented in two stages. A first stage looked at the system of cities in Colombia and identified a series of bottlenecks that limit the efficiency of the system. Three key topics were identified from the first phase diagnostics for further analysis in the second phase, in close discussion with the Department of National Planning. The three cross-cutting topics identified for a policy ‘deep dive’ in phase two were:deepening economic connectivity, enhancing coordination at a regional and metropolitan scale, and fostering efficiency and innovativeness in how cities finance themselves.