The Armenian National Assembly voted 77 to 0 to ratify the controversial gas deal.
The opposition forces boycotted the special session of the parliament, while the Republican and Orinats Yerkir Parties voted in favor of the agreement.
The deal gives the remaining 20% of shares of ArmRusGasprom Company to Russian Gazprom.
Hundreds of citizens gathered in front of the Parliament building to protest against the ratification of the agreement.
