This paper examines the ways by which organizational and institutional features of regional innovation systems shape smart specialization practices in less-developed, intermediate and advanced regions. Drawing on research from 15 European regions, it shows that the implantation of smart specialization creates challenges in all three types of regions. At the same time, there is evidence that smart specialization supports policy-learning and system-building efforts in less-developed regions and facilitates policy reorientation and system transformation in more advanced regions.