Citing informed sources, Fars News Agency said late on Tuesday that the envoys were given notification that their diplomatic postings had been terminated.
It did not give details on which ambassadors were affected and government officials were not immediately available for comment on the report, which also suggested that other Iranian embassies were in need of new personnel.
"Some of these people officially took positions during the recent riots in Iran in support of rioters," Fars said.
"It is supposed that the new ambassadors will be selected from committed experts loyal to the basis of the (1979 Islamic) revolution," it said.
The poll and its turbulent aftermath plunged Iran into its deepest internal crisis since the revolution three decades ago and exposed deepening establishment divisions.
Iranian officials have denounced some of the people who took part in huge opposition protests in the days after the June 12 election as "rioters," accusing them of attacking government buildings and destroying public property.
The moderate opposition, which says the vote was rigged to secure the re-election of hard-line President Mahmoud Ahmadinejad, has blamed authorities for the bloodshed, in which at least 26 people died.
Officials reject charges of vote fraud, describing the election as Iran's "healthiest" since the revolution.
(Reporting by Reza Derakhshi; writing by Fredrik Dahl, editing by Dominic Evans)
