The Caucasus region has always been one of the important centers of competition and cooperation between regional and trans regional powers due to its geopolitical location, energy resources, and ethnic-religious diversity. The Islamic Republic of Iran and the Russian Federation, as two regional powers and neighbors with vital interests, have complex interactions in this region that include tactical cooperation. This article analyzes the interactions of Iran and Russia in the Caucasus using the theoretical framework of structural realism (neorealism) by Kenneth Waltz. The main argument is that the anarchic structure of the international system and the distribution of power at the regional level are the main drivers of the behavior and activism of these two countries in the relatively turbulent Caucasus region. Survival, national security, and efforts to increase extend of power constitute the main goals of Iran and Russia, leading to the formation of a model of cooperation in the security, military, strategic, and economic fields (economic projects) based on balance against common threats such as Western influence and competition for regional influence in peripheral crises such as the Karabakh crisis, competition in the field of energy and transit corridors. The present study, by describing, analyzing, and explaining the characteristics of Iran-Russia relations in various historical transitions (past and present), seeks to apply the components that shape the interactions between Iran and the Russian Federation in the Caucasus from the perspective of structural realism (the anarchic nature of relations, survival and national security as the main priority for the survival of the parties, the behavioral pattern resulting from creating a balance, tactical alliance and self-help, and promoting security).