The objective of the article is to investigate innovation collaboration among firms in different types of regions in Norway. Informed by literature on innovation network and regional development, the authors examine whether firms in some regions participate more frequently in innovation collaboration than firms in other regions. They also discuss regional differences in type of innovation collaboration. The analysis is based on data from the Sixth Norwegian Community Innovation Survey (CIS), collected by Statistics Norway in 2008, which provided both descriptive statistics and could be used for logistic regression analysis. Key findings are that the likelihood of innovation collaboration is inversely related to region size, and innovation collaboration is especially prevalent among firms in rural regions. A further finding is that firms in rural regions are more involved in bridging linkages (collaboration with different type of actors) than firms in the capital and metropolitan regions. These differences are attributed to the 'organizational thinness' of rural regions, which indicate as lack of specific resources in the regions and therefore creates a need for external collaborators.