The death toll from the December protests was the highest since June
Iran has put 16 people on trial after anti-government protests in December, when eight people died in some of the most violent clashes seen in months.
Five of the defendants are charged with "waging war against God" while the others are accused of public order and national security offences.
They were all arrested over protests on 27 December when Shia Muslims gathered for the religious festival of Ashura.
Street protests have recurred in Iran since the disputed election in June.
Hardline leader Mahmoud Ahmadinejad was re-elected for a second term in a poll marred by allegations of fraud.
Hundreds of people were detained in the immediate aftermath of the Ashura Day protests.
On Thursday, Iran reportedly executed two men arrested during the unrest which followed the June election.
The executions are believed to be the first related to the protests.
Reporting Saturday's trial, Iran's state news agency said five defendants were accused of "waging war against God" and being "corrupt on earth" - both crimes punishable by death under the Iranian legal system.
The others, the agency reported, were accused of "gathering and conspiring against security, propaganda against the system and seeking to harm security by inciting unrest and riot".