During World War II about 100,000 Red Navy sailors fought on land. At the beginning of the war, the navy had only one brigade of marines in the Baltic fleet, but began forming and training other battalions. These eventually were
- six naval infantry regiments, comprising two battalions, each with 650 personnel
- 40 naval infantry brigades of 5-10 battalions, formed from surplus ships' crews. Five brigades were awarded Gvardy (Guards) status.
- numerous smaller units.
The military situation demanded the deployment of large numbers of marines on land fronts, so the Naval Infantry contributed to the defense of Moscow, Leningrad, Odessa, Sevastopol, Stalingrad, Novorossiisk, Kerch.
The Naval Infantry conducted over 114 landings, most of which were carried out by platoons and companies. In general, however, Naval Infantry served as regular infantry, without any amphibious training.
They conducted four major operations: two during the Battle of the Kerch Peninsula, one during the Caucasus Campaign and one as part of the Landing at Moonsund, in the Baltic.
During the war, five brigades and two battalions of naval infantry were awarded Guards status. Nine brigades and six battalions were awarded decorations, and many were given honorary titles. The title Hero of the Soviet Union was bestowed on 122 members of naval infantry units.
The Soviet experience in amphibious warfare in World War II contributed to the development of Soviet operational art in combined arms operations. Many elements in the Naval Infantry were parachute trained and the SNI conducted more drops and successful parachute operations than the VDV.
The Naval Infantry was disbanded in 1947, with some units being transferred to the Coastal Defence Force.