More than 3,000 candidates are running in- but all of them are conservatives.
The liberal opposition that blossomed so dramatically in 2009 has since been crushed. Its activists are deep underground, and its leaders under house arrest.
No matter who wins today's elections, the hardliners will be in charge.
The regime wants a big turnout to help legitimize its anti-Western position, and its refusal to back down on its nuclear program.
"Iran's policy with the U.S. won't change. Iran's policy with Israel won't change," says professor Sadeq Zibakalam, who teaches politics at Tehran University. "Nothing will change."
What is changing, however, is Iran's economy.
U.S. sanctions - designed to pressure Iran over its nuclear ambitions - are starting to hurt.
The prices of ground meat and tea are up by 50 percent since January. The price of eggs has more than doubled.
And, because Iranian currency has lost nearly half its value against the U.S. dollar, the cost of imported goods - like machinery or medicine - is skyrocketing.
"Of course we are worried," a man identifying himself only as Hassan tells CBS News at market in Tehran. "Everyone is worried."
It is a crisis that will only get worse - as new, even tougher sanctions that will cut off Iran's oil revenue are due to take effect in June.
Click on the player above to see Elizabeth Palmer's full report from the Iranian capital