According to the paper, the satirical article by Onion cited a fake Gallup poll, which found that some 77% of white, rural voters would rather go to a baseball game or have a beer with Ahmadinejad rather than with Obama.
Fars, which loyally prints the anti-Western and anti-Israeli tirades of senior Iranian officials, copied the entire Onion article without giving any indication of its source, and also printed a short bulletin on it in English, the paper said.
Following the publishing, Will Tracy, the editor of the Onion, released a statement joking that Fars was a 'subsidiary of the Onion'.
"They have acted as our Middle Eastern bureau since the mid 1980s, when the Onion's publisher, T Herman Zweibel, founded Fars with the government approval of the late Supreme Leader Ayatollah Khomeini. The Onion freely shares content with Fars and commends the journalists at Iran's Finest News Source on their superb reportage," Tracy added.
Previously, several other news organisations have fallen victim to the US spoof site, Onion's mock-serious news style, the paper added.