As the marathon negotiation between Iran and the P5+1 countries (China, France, Germany, Russia, the United Kingdom, and the United States) nears its third self-imposed deadline on June 30, many around the world wonder if this round of negotiations is going to resolve all remaining issues, and if so, whether the officials involved are going to be able to sell the deal they have worked out back in their own capitals. As to whether or not a deal will be reached, diplomats from Iran as well as the P5+1 countries have consistently been cautiously optimistic. While all sides indicate that they are committed to reaching a deal by the June 30 deadline, recent reports suggest that gaps remain between concrete positions on the main elements of a deal. And as negotiators struggle with various elements of the deal outside their capitals, there is significant controversy inside the capitals on what would constitute a “good deal.” The U.S. Congress has passed legislation giving Congress at least a month to review the details of any agreement reached before President Obama could waive any congressionally imposed sanctions on Iran. Lawmakers and officials in Tehran have been pressing their case that any deal that would not result in speedy termination of sanctions or would open Iran’s sensitive non-nuclear military and security installations to Iran-specific inspections is unacceptable. To better understand the domestic political environments that constrain how much negotiating room the key players have, the Center for International and Security Studies at Maryland (CISSM) has conducted several studies of American and Iranian public opinion on the nuclear negotiations. Its first study of American public opinion, “Americans on Negotiations with Iran,” was conducted in collaboration with the Program for Public Consultation in July 2014, followed by another study which was released on March 3, 2015. Both of these reports are available at www.cissm.umd.edu. CISSM also conducted a study of Iranian public opinion on the nuclear negotiations in collaboration with the University of Tehran Center for Public Opinion Research (UTCPOR) in July 2014, focusing mostly on the steps Iran would be willing to take in return for removal of unilateral and multilateral sanctions, and published the results of that study on September 17, 2014. The current study was conducted after Iran and the P5+1 reached an understanding regarding the main elements of the final deal in Lausanne, Switzerland. It seeks to illuminate the specific views and preferences of Iranian citizens regarding the ongoing nuclear negotiations, their support for a deal along the lines of the framework understanding, their assumptions regarding the elements of the final deal, and their expectations from a deal. This study also explores a broad range of Iranian political preferences and attitudes that shape the context in which the nuclear negotiations are occurring.