In this article, the Islamic Republic of Iran’s willingness to become a full member of the Shanghai Cooperation Organization SCO under the shadow of Iran’s nuclear tension with the US is evaluated with a special focus on the conditions, which prepares the grounds for the establishment of the Shanghai Five in 1996, its transformation to the SCO in 2001 and Post Cold War developments and the United States’ presence in the region after the 9/11 terror attacks to the US. Iran’s relations with the six SCO members is also given as an additional information in order to provide the reader with a general perspective about the possibility of Iran’s prospective membership to the SCO and to analyze the answers to these questions: Is it possible for Iran, which is under great pressure of the US due to its nuclear program, to become a full member to the SCO in the near future? If it is possible, what would be the repercussions in the US?