This textbook helps students and readers navigate the various factors ranging from the legacy of the past, ethnic, sectarian differences, and cultural rivalry to the impact of colonial rule, modernization and state building, plus the evolving nature of the international political system and great power policies in shaping Arab-Iranian relations in the last seven decades. The first part of this book looks into factors such as history, ethnic, sectarian and cultural issues that have shaped Iran's relations with Arab states. It explores the impact of the process of modernization and state-building in the Arab world on these relations, plus the legacy of colonialism and the shifting dynamics of international politics and the evolution key global players' policies towards Iran and the Arab states. The second part examines case studies in the evolution of Iran's relations with several key Arab states, including Egypt, Syria and Lebanon, Iraq, Saudi Arabia and the smaller Persian Gulf Arab states. By highlighting the complex set of factors and their interactions that have shaped Arab-Iranian relations, the book hopes to be a corrective to the simplistic and reductionist interpretations of these relations. This approach shows how a variety of factors and their interactions have shaped these relations; sometimes they have exacerbated the conflictual aspects of these relations and at other times have fostered accommodation and even cooperation.