The incident in the Iranian city was an apparent imitation of a similar attack on former U.S. president George Bush in Iraq last year.
Urmia News, the Iranian site, reported that Ahmadinejad was in a car en route to an election rally when the shoe was thrown. Ahmadinejad was traveling to a local stadium where he was meant to deliver a speech ahead of upcoming presidential elections.
According to the report, a hat was also thrown at the Iranian president before his convoy sped away from the scene.
The incident was not reported by Iran's major news outlets. But it has been widely commented upon in the Islamic Republic's blogosphere, which is viewed as one of the most developed in the world. It is one of the key tools for disseminating information that contradicts the position of the regime that controls the traditional media.
A number of pro-Ahmadinejad bloggers denied the report, claiming it was a rumor spread by "monarchists" and "anti-revolutionaries," the accepted terms for members of the Iranian opposition.
Urmia News said the incident occurred after riots erupted in the city in response to harming by the convoy of an elderly pedestrian who had sought to hand Ahmadinejad a letter.
Urmia News did not say when the incident transpired, but it apparently took place at some point over the last few days.
In December last year, an Iraqi television news reporter threw his shoes at Bush and called him a "dog" in Arabic, during a press conference in Baghdad. The act triggered a spate of copycat shoe-hurling incidents across the world.