Joint Comprehensive Plan of Action (JCPOA) was reached in Vienna on July 14 2015, between Iran, the P5+1, and the European Union (EU), and was formally put into action on January 16 2016. This accord is considered to be one of the most important international agreements since World War II. JCPOA has a key role in shaping the future prospects of Iran-EU relations. As such, this article will examine the foundation for collaboration between the two parties in the post-JCPOA era. In this context, the paper assesses the positive outcomes of the accord on economic cooperation, along with the potential challenges in Iran-EU relations at the aftermath of the US’s withdrawal [from the agreement] in the post-JCPOA era.** The main hypothesis of this paper is that it is in the best interests of both Iran and the EU to directly and fully implement JCPOA. Equally important, both parties will benefit from limiting the influence of external parties, in particular the United States. Under these conditions, we can expect that both parties will seek to expand economic, political, and cultural relations during the coming years.