The United States Geological Survey said it had a magnitude of 6.2 on the Richter scale.
So far, there are no reports of damage or casualties.
The earthquake was felt from the Caspian Sea provinces to the central city of Isfahan and the northwest city of Ardebil.
The quake shook buildings in Tehran and people in the streets screamed, with the 6.8 magnitude earthquake in Bam which left over 20,000 people dead still fresh in their memories.
There were also reports that some windows in western Tehran were shattered.
Reuters reported that the Geological Survey, monitored from London, said on its Web site: "A strong earthquake occurred at 12:38:46 (GMT) on Friday...The magnitude 6.2 event has been located in northern Iran."
The Iranian Red Crescent said they have not yet received any calls for aid or assistance.
IS/HG
End
MNA