The corporate citizenship (CC) concept introduced by Dirk Matten and Andrew Crane has been well received. To this date, however, empirical studies based on this concept are lacking. In this article, we flesh out and operationalize the CC concept and develop an assessment tool for CC. Our tool focuses on the organizational level and assesses the embeddedness of CC in organizational structures and procedures. To illustrate the applicability of the tool, we assess five Swiss companies (ABB, Credit Suisse, Nestlé, Novartis, and UBS). These five companies are participants of the UN Global Compact (UNGC), currently the largest collaborative strategic policy initiative for business in the world (www.unglobalcompact.org). This study makes four main contributions: (1) it enriches and operationalizes Matten and Crane’s CC definition to build a concept of CC that can be operationalized, (2) it develops an analytical tool to assess the organizational embeddedness of CC, (3) it generates empirical insights into how five multinational corporations have approached CC, and (4) it presents assessment results that provide indications how global governance initiatives like the UNGC can support the implementation of CC.