Hello, and thanks for your question.
It's difficult to find alcoholic beverages for sale in Iran, because "alcohol ingestion is strictly illegal under Islamic Religious Law in Iran and those caught can be whipped, fined, or jailed. However, the WHO reports: "Religious minorities can buy alcoholic beverages from very few specifically licensed shops owned by shopkeepers of the same minority." An Erowid reader describes the law this way: "It is usually illegal to buy or sell alcohol in Iran, but there are some exceptions. Christians (Armenians), Jews, and some other minorities are allowed to sell alcoholic beverages. These minorities are also only supposed to sell alcohol to members of their own minority, but they don't really ask--or even care--about what your background is. A lot of non-minority Iranians drink, but they do it secretly." See WHO's Alcohol Policy PDF
. (thanks K,S) (last updated Oct 6 2009)" (source: http://www.erowid.org/chemicals/alcohol/alcohol_law.shtml)
If you can find a store run by a non-Muslim person/family, they will sell you alcoholic beverages, if you are of age. If you are in Iran now, inquire of a tour guide or hotel where you are staying, where you might find alcoholic beverages sold by non-Islamic stores.
I hope this helped you.