The vote for city and rural councils and the Assembly of Experts will show if the president's rivals are regaining popularity even if the results have no direct impact on policy.
The two elections come at a time when Tehran is facing growing international pressure over its controversial nuclear program. Authorities have said a high turnout will prove popular support for the ruling government.
"We hope [our foreign opponents] will change and desist their grudge against the Iranian nation, because the nation of Iran has made a big decision and is moving with determination and authority on the path of greatness," Ahmadijejad told reporters in Tehran after he voted this morning.
Among the some 160 candidates approved to run in the elections there is only one is not a cleric. Some 500 candidates applied to be candidates in the assembly elections, but about two-thirds of them were disqualified.
(with material from Reuters)