Do sanctions reduce military spending in Iran? To answer this question, we use annual data from 1960 to 2017 and the autoregressive distributed lag (ARDL) model. We show that an increase in the intensity of sanctions is associated with a larger decrease in military spending in both the short and the long run. Each level of increase in the intensity of sanctions with respect to our coding approach decreases military spending in the long run by approximately 33%, ceteris paribus. We also find that only the multilateral sanctions, in which the United States acts in conjunction with other countries to sanction Iran, have a statistically significant and negative impact on military spending of Iran in both the short and the long run. Multilateral sanctions reduce Iran’s military spending by approximately 77% in the long run, ceteris paribus. The results remain robust when controlling for other determinants of military spending such as gross domestic product (GDP), oil rents, trade openness, population, quality of political institutions, military expenditure of the Middle East region, non-military spending of government and the war period with Iraq.