The army exercised ways to confront chemical strikes, help the injured and decontaminate the area, the report said without giving further details.
"The exercise proves our country's high military capabilities", former president Akbar Hashemi Rafsanjani, who attended the drills Sunday, commented.
"If our enemies are aware and informed of our powers they will never take the risk to attack us", Rafsanjani, who heads the powerful Expediency Council, the nation's highest arbitration body, added.
The report did not say from where Iran expected a chemical strike to come. Its troops were subjected to gas attacks by Iraq during their 1980-1988 war, and fears have been voiced that Baghdad might use chemical weapons in case of an attack by the United States.