The foreign policy of the Islamic Republic of Iran between 1978 and 2011, along with the continuity of some identity principles and components, has undergone changes in strategies, tools, and methods of foreign action. At the level of principles and norms, explaining the simultaneous nature of this continuity and change requires examining the relationship between identity structures and the agency of political elites. With the aim of explaining this relationship, the present study answers the question of how identity structures and elite agency led to the continuity and change of the foreign policy of the Islamic Republic of Iran during the period 1978–2011. The hypothesis of the study is that established identity structures, by determining semantic, normative frameworks, and legitimate limits of action, provide the basis for the continuity of the fundamental principles of foreign policy; in contrast, the agency of political elites, by interpreting, redefining, and prioritizing these principles, provides the basis for changes in strategies, tools, and priorities of foreign policy. Using a descriptive-analytical method and within the theoretical framework of structuralism, this study examines the interrelationship between identity structures and elite agency in the developments of Iran's foreign policy. The findings of the study show that principles such as independence, negation of domination, dignity, wisdom, and expediency, as components of the identity structure of the Islamic Republic, have enjoyed relative continuity during the period under study; however, their interpretation and prioritization have changed under the influence of elite agency and domestic and international conditions.