The court found Pylev and nine other members of his organized criminal group guilty of murdering 11 people, attempted murder, banditry and of forming a criminal group.
Two of the nine defendants, Sergei Makhalin and Oleg Mikhailov, were also sentenced to life imprisonment, while the rest received from five to 25 years in prison.
"This is the first verdict of life imprisonment in my practice. I consider the verdict extremely severe," the lawyer for Pylev said, adding that he would appeal the verdict at the Supreme Court as he believes the ruling was illegal and biased.
It is the second sentence for Pylev. Last September, a Moscow court handed down a 22-year sentence after finding him guilty of the murder of contract killer Alexander Solonik and his girlfriend, Svetlana Kotova.
Investigators said the so-called Orekhovo-Medvedkovo gang, a Moscow-based group formed in the early 1990s, later split into two factions as gangsters sought to reap the rewards of Russia's path to capitalism in the era of the "Wild, Wild East."
In August 2005, the Moscow City Court sentenced 10 gang members to prison terms ranging from eight and a half to 24 years after they were convicted on 14 counts of premeditated murder in which 18 people were killed, including Solonik. Eight of the defendants pleaded guilty.