In Tehran, tens of thousands of marchers gathered at Azadi Square, one of the capital's most iconic monuments built by the United States-backed shah and renamed after the victory of the forces loyal to Khomeini.
Iran organises the nationwide rally every February 11 to highlight the size of grassroots support for the revolution, which replaced Shah Mohammad Reza Pahlavi's government with an Islamic Republic under Supreme Leader Ayatollah Ruhollah Khomeini.
Thousands of others also gathered in other cities, including the holy city of Mashhad.
Al Jazeera's Zein Basravi reports from Mashhad, where he provides a first-hand experience of celebrations.
Additionally, Foad Izadi, professor of international relations at Tehran University, tells Al Jazeera how Iran has taken a more militaristic approach to diplomacy as a result of US President Donald Trump's decision to break the 2015 nuclear agreemen
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