Purpose – Social entrepreneurship has become a growing field of research interest. Yet, past research has been held back by the lack of a rigorous measurement instrument. Rather than defining social entrepreneurship as an organizational form that a venture does or does not have, this paper agrees with Dees and Anderson (2006) that the construct is better thought of as a set of practices, processes and behaviors that organizations can engage in to a higher or a lesser degree. In other words, the construct is a set of behaviors that any organization can engage in. The purpose of the paper is to develop scale items to measure the construct of organizational social entrepreneurship (OSE). Design/methodology/approach – Drawing on previous literature, this paper first develops and then validates scales for measuring OSE as a third-order formative construct. As its second order, the scale includes three components that capture the heterogeneity of the OSE concept: social change intention,commercial activity and inclusive governance. Findings – The OSE scale is developed and tested through a sample of 182 nascent social enterprises from 55 different countries in the world and then revalidated using a second sample of 263 mature social enterprises from 6 European countries. Results suggest that the scale items exhibit internal consistency, reliability, construct validity and nomological validity. Research limitations/implications – The scale presented here offers an important new venue for social entrepreneurship theorizing. First, it allows scholars to take a broad approach toward a diverse field and to study OSE behavior in any empirical field in which it may occur. Second, the scales also allow for more focused theorizing.Scholars are encouraged to delve into the antecedents of all three components presented here and to study the different performance effects they have in terms of likelihood to survive, growth rate or potential to achieve financial sustainability. Originality/value – The paper develops a multidimensional construct for OSE. In particular, the authors propose scale items for three central components of social entrepreneurship,namely, social change intentions, commercial activities and inclusive governance. The scales thus measure the three formative dimensions identified by Dees and Anderson (2006) and Defourny and Nyssens (2010).