The two countries have been rapidly building closer ties
Russian and Venezuelan energy firms have agreed to work on an energy cooperation pact, at a meeting of their respective presidents.
Venezuela's Hugo Chavez was in the southern Russian city of Orenburg with Russia's Dmitry Medvedev.
The two countries have been rapidly building closer military and economic ties, and have spoken of their opposition to US global dominance.
The latest deal calls for broader co-operation on oil and gas production.
Mr Chavez and Mr Medvedev smiled and clapped as the heads of Russian gas giant Gazprom and Venezuelan energy firm PDVSA put pen to paper.
"Esteemed president, dear Hugo," Mr Medvedev beamed.
"This dynamic in our relationship points to the solid foundation of our ties. Our co-operation is multi-faceted... it includes economic and military ties."
Russia withdrew from Latin America when the Soviet Union collapsed but there are now signs of a new Russian assertiveness in the region, says BBC analyst Steven Eke.
Venezuela is already one of the best customers of the Russian defence industry, with signed contracts promising to bring Russia more than $4bn (£2.17bn) in weapons sales.
But, our analyst says, it is the political dimensions of the relationship that lead many analysts to ask whether Russia is now actively trying to create a counterbalance to American influence, starting in South America.
Russia is increasing its military links to Venezuela
President Medvedev has echoed his predecessor, Vladimir Putin, in calling for what he terms a "multipolar world".
Yet it is often forgotten that Mr Putin actually oversaw Russia's final military withdrawal from the southern American region, when he closed an electronic listening base in Cuba in 2002.
Now, a much more assertive Russia appears to be probing for ways of organising a return to the region, our analyst notes.
Two long-range Russian strategic bombers recently visited Venezuela and Russian warships are currently en route to the Caribbean Sea for joint exercises with the Venezuelan navy.
One of the most curious elements of the new relationship between Russia and Venezuela is the man apparently running it from the Russian side.
Igor Sechin is a deputy prime minister, one of Vladimir Putin's closest associates, and strongly anti-American.
He is widely thought to have worked for Soviet intelligence in African satellite states in the 1980s.
Mr Sechin has been the most visible face in Russia's recent contacts with the equally anti-American president of Venezuela, Hugo Chavez.