Russia's emergencies ministry said the Il-76 transported "23 tonnes of humanitarian aid" including food and tents to Yemen's capital Sanaa.
AFP journalists saw the plane at Sanaa airport -- which is controlled by Shiite Huthi rebels -- and were told it contained aid.
The plane was then set to fly back to the Russian capital Friday with some 75 people on board who wanted to quit the strife-torn city, the ministry said.
Russia last sent planes to Yemen's capital in July, with Moscow saying they had some 46 tonnes of aid.
Around 5,000 people have been killed in the conflict since March, more than half of them civilians, according to UN estimates.
The conflict in Yemen has pitched regional rivals Saudi Arabia against Iran. Russia is allied to Iran as the main backers of President Bashar al-Assad in the conflict in Syria.