This article contributes to the internationalization of survey methodology by discussing a case from a totalitarian state, the Islamic Republic of Iran. In 2020, GAMAAN (The Group for Measuring and Analyzing Attitudes in Iran) conducted an online survey on religion. The survey had 50,000 participants, around 90 percent of whom lived in Iran. This article discusses the result that, after weighting, 8 percent identified as Zoroastrian—many times the number of Zoroastrians as recorded by scholarship on Iranian Zoroastrianism. We dub this phenomenon “Survey Zoroastrianism” and offer an explanation for this finding. After describing the position of Zoroastrianism in modern Iran and adding two further online surveys conducted by GAMAAN in 2022, we discuss the Survey Zoroastrians’ demographics and their religious and political views. The analysis shows that participating in surveys beyond the government's control provided affordances for performing alternative identity aspirations tied to notions of nationalism and civilizational heritage.