On July 14, 2015, the United States, Iran, and five other world powers announced that they had agreed on a Joint Comprehensive Plan of Action (JCPOA) to resolve international concerns about Iran’s nuclear program. In return for Iran strengthening its commitments never to pursue nuclear weapons, sharply limiting its dual-use capabilities, and allowing greater international scrutiny of its nuclear program, the United Nations Security Council, the European Union, and the United States agreed to lift nuclear-related sanctions on Iran. Both the nuclear deal and Iranian President Hassan Rouhani were immensely popular in Iran right after the JCPOA was announced, in part because the public thought that the terms were more generous toward Iran than they actually were, and because people had high expectations about economic and political benefits. Reactions in the United States were much more mixed. A smaller majority of the American public supported the deal, but critics in Congress came close to blocking its implementation because they worried about what Iran would do if it received a windfall from sanctions relief and hoped that tightening sanctions further could convince Iran to give up all dual-use nuclear capabilities. It’s appropriate to assess how Iranian public opinion has changed in the year since the deal was signed and the six months since sanctions relief began to be implemented, given that U.S. and European leaders frequently assert that Rouhani was elected with a mandate to improve Iran’s economy by using nuclear diplomacy to get sanctions relief. Comparing shifts in Iranian public opinion over time also offers a way to test some of the predictions made by congressional critics, including that there would be a crack-down on human rights in Iran to appease the opponents of increased engagement with the West, or that giving the Iranian public only a small taste of the economic and political benefits that could flow from becoming a “normal” country would increase pressure for more sweeping changes to Iran’s domestic and foreign policies. This survey of Iranian public opinion is the sixth in a series conducted during and after the negotiations that produced the JCPOA by the Center for International and Security Studies at Maryland in collaboration with the Program on Public Consultation and Iranpoll.com. Some of the same questions have been asked consistently since July 2014, when negotiations had been underway for many months, but the two sides remained far apart on some important issues. Some were reworded to reflect important contextual changes, such as public understanding about the main elements of the JCPOA and the Iranian parliamentary elections earlier this year. Some new questions have been added to find out what the Iranian public thinks about issues that have become particularly salient in recent months, such as the extent to which those who have not yet seen any economic benefits from the JCPOA hold Rouhani responsible or blame factors beyond his control. The previous reports in this series, a set of assessments about American attitudes towards nuclear diplomacy with Iran, and a collection of related articles are available at: http://www.cissm.umd.edu/projects/security-cooperation-iran-challenges-and-opportunities.