This article analyses the United States and Great Britain policy towards Iran between 1951 and 1953 when National Front leader Mohammad Mosaddegh was a Prime Minister. This particular period of Iranian history is directly related to the nationalization of Iranian oil industry carried out by this government at the expense of Great Britain. Important thread of this study is a question of British and American involvement in Iran as the British-Iranian conflict had been rising including diplomatic, economic and finally intelligence effort. It shows also the process of developing factors that influenced it. The paper points out challenges of British-American relations at this stage as well as difficult cooperation plane during the broader context of the Cold War. It finally determines clearness of Central Intelligence role in the Coup ended by overthrown of Iranian nationalists and replaced it by new suitable government for both Anglo-Saxon States.