Organizational cultures exist in industries and organizations worldwide. Publications have proposed definitions, culture basis, training, and applications relevant to the cultures found in international nuclear materials management organizations, which have responsibilities ranging from packaging, transportation, and disposition to international safeguards and physical security. In particular, the IAEA (International Atomic Energy Agency) has convened consultants’ meetings on nuclear safety culture and nuclear security culture and subsequently issued definitions, standards, and guidance for these two disciplines. In comparison, the IAEA has not held a consultants’ meeting on culture for the international safeguards discipline, nor has the IAEA issued guidance or standards for IAEA international safeguards culture. In addition, international safeguards culture is not defined in the IAEA Safeguards Glossary. The overall importance of culture was demonstrated in a statement attributed to Peter F. Drucker, “father of management thinking”: “Culture eats strategy for breakfast!” The study of organizational culture is widely applicable. This paper briefly identifies definitions and guidance issued by the IAEA for “nuclear safety culture” and for “nuclear security culture,” which frequently reference Professor Edgar H. Schein’s concept of organizational culture. Edgar H. Schein, a pioneer in organizational culture studies, has performed groundbreaking work since the 1980s and is widely recognized in the nuclear industry. Using the seminal work of Edgar H. Schein and Peter Schein, this paper explores the application of the Schein organizational culture concept and definition to occupational organizations. It concludes with recommendations, particularly for the IAEA to convene a consultants’ meeting for developing a working definition and for issuing guidance for international safeguards culture.