Based on the seven case studies analysed in this volume, this chapter concludes that national development banks (NDBs) have been successful in many cases in supporting innovation and entrepreneurship, key new sectors like renewable energy, and financial inclusion. They have developed new instruments, such as far greater use of guarantees, equity (including venture capital) and debt funds, and new instruments for financial inclusion. The context in which they operate is key to their success. Active countercyclical policies, low inflation, fairly low real interest rates, a well-functioning financial sector, and competitive exchange rates are crucial. They are also more effective if the country has a clear development strategy, linked to production sector strategies that foster innovative sectors. Under these conditions, the chapter argues that there is great need for a larger scale of NDB activity in Latin America and in developing countries in general.