The Persian Gulf, due to its geopolitical position, energy resources, and vital waterways, has always been a focal point for great power rivalries and regional tensions. The Islamic Republic of Iran, long relying on the principles of its foreign policy, believes that ensuring sustainable security in this region is possible only through intra-regional cooperation and the formation of an order based on collective security among neighboring countries, and has consistently declared its opposition to the presence of extra-regional powers. In the post-war period, coinciding with the decline of US influence in the Persian Gulf and structural transformations in the international system, a suitable context has emerged for redefining regional security arrangements. This article seeks to identify and explain the requirements of the Islamic Republic of Iran's neighborhood policy for realizing a collective security order in the Persian Gulf during this period. It attempts to answer the following question using a descriptive-analytical approach, library resources, internet sources, and interviews: What requirements and solutions should Iran's neighborhood policy pursue to achieve a collective security order? In response, the article's hypothesis is that in the post-war era in the Persian Gulf, to realize collective security, Iran needs to consider requirements such as prioritizing neighborhood policy, strengthening good neighborly relations, establishing regional dialogue institutions, and developing common security mechanisms with the Persian Gulf countries (such as Saudi Arabia, the UAE, Kuwait, Qatar, Bahrain, and Iraq)