This publication highlights the importance of promoting growth in all types of OECD regions, particularly in underdeveloped ones. Helping underdeveloped regions to catch up will have a positive impact on a country’s national growth; in some cases more so than in already well-developed regions. Furthermore such growth helps to build  a fairer society, in which no territories and their people are left behind. An important question is whether this potential to catch up is possible?  The evidence suggests that this IS the case.  Examinations of patterns of growth reveal that underdeveloped rural and intermediate regions tend to grow faster. Their catching-up potentially largely depends on human capital development, infrastructure and innovation-related activities but also on institutional factors and policies. This publication is based on anlaysis among all OECD regions and 23 case study regions from ten OECD countries over the period 1995-2007.