This study of the OECD deals with cross-border cooperation between regions in the field of innovation policies, through the analysis of six cross-border areas : the Bothnian Arc (Sweden-Finland); Hedmark-Dalarna (Norway-Sweden); Helsinki-Tallinn (Finland-Estonia); Ireland-Northern Ireland (United Kingdom); the Oresund Region (Denmark-Sweden); and the Top Technology Region/Eindhoven-Leuven-Aachen Triangle (Netherlands-Belgium-Germany). The study addresses the questions of the conditions in which cross-border cooperation is positive for economic development, the kind of governance approaches or policy instruments that can be used to facilitate such cooperation in innovation.