However, the conference was initiated by President Mahmoud Ahmadinejad, who has described the Holocaust as a "myth" and called for Israel to be wiped off the map.
The organizers, the Foreign Ministry's Institute for Political and International Studies (IPIS), said the two-day conference has drawn 67 foreign researchers from 30 countries.
In his opening speech, the institute's chief, Rasoul Mousavi, said the conference "seeks neither to deny or prove the Holocaust.
"It is just to provide an appropriate scientific atmosphere for scholars to offer their opinions in freedom about a historical issue," Mousavi said.
He said the conference provided an opportunity to discuss "questions" about the Holocaust away from Western taboos and the restrictions imposed on scholars in Europe.
Iranian Foreign Minister Manouchehr Mottaki is scheduled to read a message to the conference from President Ahmadinejad, who has said that the killing of six million Jews by the Nazi German regime during World War II was a "myth" and "exaggerated."
The president has repeatedly downplayed the Holocaust, questioning why it has been used to justify the creation of Israel at the cost of Palestinian lands -- a view popular among Iranian hard-liners.
Iran has spent months preparing for the conference, even publicizing it during the September visit to Tehran of U.N. Secretary-General Kofi Annan, who contradicted his hosts by saying the Holocaust was a historical fact and that an exhibition of anti-Holocausts cartoons, then on display in the city, promoted hatred.
The conference has been condemned by Germany, where denying the Holocaust is illegal, as well as by Israel and the United States.