January 8, 2012
"Iran and Russia replaced the U.S. dollar with their national currencies in bilateral trade, Iran’s state-run Fars news agency reported, citing Seyed Reza Sajjadi, the Iranian ambassador in Moscow.
The proposal to switch to the ruble and the rial was raised by Russian President Dmitry Medvedev at a meeting with his Iranian counterpart, Mahmoud Ahmadinejad, in Astana, Kazakhstan, of the Shanghai Cooperation Organization, the ambassador said."

Iran, Russia Replace Dollar With Rial, Ruble in Trade, Fars Says - Bloomberg