State TV showed footage of missiles fired from the coast and the fast boats striking the ersatz American carrier, which appeared to be a replica seen in a shipyard in the southern port of Bandar Abbas last year. The drills also included Guard forces shooting down a drone and planting undersea mines.
Footage aired Wednesday did not show that the assault had managed to sink the mock-up, but it was heavily damaged.
The Guard's chief commander, Gen. Mohammad Ali Jafari, said the drills send a "message of (Iran's) might" to "extraterritorial powers," a reference to the United States.
Cmdr. Kevin Stephens, the spokesman for the U.S. Navy's 5th Fleet in Bahrain, said the Americans were monitoring the drills, which had no effect on maritime traffic. He downplayed the simulated attack on the carrier, saying the U.S. military was "not concerned about this exercise."
"We're quite confident of our naval forces' ability to defend themselves," he said. "It seems they've attempted to destroy the equivalent of a Hollywood movie set."
The U.S. routinely stations at least one aircraft carrier and other warships in and around the Gulf.
It and its allies conduct periodic naval exercises of their own in the region, including ones aimed at countering the threat from undersea mines that could be used to block ship traffic through the strait.
The American aircraft carrier USS Carl Vinson is currently deployed in the Gulf, as is the French carrier Charles de Gaulle. Planes from both vessels are carrying out airstrikes against the self-proclaimed Islamic State of Iraq and al-Sham (ISIS) group, which has seized roughly a third of Iraq and Syria.
Iran backs Syria's government and is supporting Iraq in its fight against the militants, but it is not part of the U.S.-led international coalition against the extremist group.
The drills were not publicly announced in advance, but the Guard has held similar military exercises around this time of year. The last one, in February 2013, featured "suicide drones" that attack enemies kamikaze-style.
The Guard, which has a 200,000-strong force, is different from the regular army and is charged with protecting the ruling system. It also controls the paramilitary Basij militia, for which there are no precise personnel figures available.
Iran put the Guard in charge of defending the country's territorial Gulf waters in 2008 as Iran turned its attention toward beefing up its naval and air defense forces.
Iran is currently negotiating an agreement over its disputed nuclear program with the United States and five other world powers in exchange for relief from crippling economic sanctions. The two sides hope to reach a framework agreement next month and a final deal in June.
Western nations have long suspected Iran is covertly seeking a nuclear weapons capability charges Tehran denies.
In a speech Wednesday in the holy city of Qom, President Hassan Rouhani called for all sanctions to be lifted once a final nuclear accord is reached.
"Our opposite negotiating party has to know that the end of these talks and the result of a deal must be lifting of the entire oppressive and illegal sanctions," he said. "In the negotiations, we will not accept any imposition, humiliation or continuation of the sanctions."