Under the deal, signed in March by Bulgaria, Greece and Russia, a 280-kilometer (175-mile) pipeline will bring Russian oil from Bulgaria's Black Sea port of Burgas to Alexandroupolis in northeastern Greece, bypassing the environmentally vulnerable Bosporus Straits.
Parliament voted 109-19 with 3 abstentions to ratify the project, tentatively scheduled for completion by 2010.
The Greek parliament and the lower house of the Russian parliament, the Duma, have already approved the agreement.
The 36-inch (90-centimeter) pipeline would initially carry 700,000 barrels of oil a day, with capacity set to eventually rise to more than 1 million barrels a day.
Bulgaria will receive annually between US$35-50 million (EUR26-38 million) from transit fees and 1,000 new jobs would be created, the government said.
Russia will have a 51 percent share in the project, while EU members Bulgaria and Greece will have 24.5 percent each.