This chapter shows that regional aid for trade has a critical role to play in boosting the participation of particularly low income and least developed countries in regional production networks, and in enabling them to connect and move-up value chains. The chapter highlights that one of the main motivations of the trend towards regional integration is the need to reduce barriers in regional production networks. Barriers to trade, bureaucratic bottlenecks, and infrastructure deficiencies reduce the attractiveness of countries as spokes in the hubs of the production networks. Regional aid-for-trade programmes – which have increased significantly since the 2002-05 baseline – are an effective means to address these constraints. The chapter highlights that while regional aid-for-trade programmes are inherently complex because of the need to involve and coordinate multiple governments, their various agencies and a multitude of private stakeholders, they constitute a cost-effective approach to helping countries achieve their trade and development objectives.