Cross-border innovation cooperation (CBIC) has been heralded as one of the corner stones of innovation-driven growth opportunities for firms located in cross-border regions (CBRs). The success of this cooperation is affected by varying types of proximities identified in the literature as: geographical, institutional, cultural, cognitive, technological, organizational and social. Although the topic has been widely discussed, the validation of the concept of proximity vis-à-vis CBIC has been persistently hindered by a lack of readily available empirical metrics. Therefore, this research note attempts to operationalize the varying types of proximity-in relation to CBIC-in the form of a questionnaire tested through pilot studies of two CBRs, at the Finnish-Swedish and Danish-German border, and for two contrasting service industries, namely knowledge-intensive business services and tourism. The findings indicate that the developed survey metrics are effective in depicting the phenomenon of proximity. The foundational work undertaken in this research note provides a platform, and catalyst, for more extensive investigations of the topic.