During and after World War II, large-scale looting and seizure of cultural, industrial, and personal property took place in areas of Central and Eastern Europe at the hands of the Soviet armed forces.

The art seizure happened after the plunder of Russian and related culture's art treasures by the German soldiers and 'art brigades' during the initial years of World War II when Germany rapidly advanced into Russian territory. From the Soviet government perspective, it was an attempt at self accomplished reparations for the USSR's wartime cultural losses, coupled with the traditional desire for enrichment exhibited by the victorious soldiers. The looted items ranged from artworks and museum collections to industrial equipment and household goods. Despite some early post-Soviet efforts at restitution, Russia has largely maintained legal and political justifications for retaining these materials, often citing them as compensation for Nazi crimes against the USSR, and ignoring the fact that some of the items it holds belonged to other victims of Nazi looting.

Plunder and looting has been a traditional consequence of military activities through human history. Russian forces have plundered before the establishment of the USSR, for example during World War I, and in the conflicts following it, such as the Soviet invasion of Poland in the aftermath of World War I.

In 1943 Soviet artist and scholar Igor Grabar proposed tit-for-tat compensation of Soviet art treasures destroyed in World War II with art to be taken from Germany. The idea was approved by the Soviet authorities, leading to the establishment of the Bureau of Experts, tasked with compiling lists of items which the USSR wanted to receive as "restitution in kind" to compensate for its own cultural losses, both from state institutions but also from various private collections. The Bureau was headed by Grabar himself; its other members included Viktor Lazarev and Sergei Troinitsky. While this topic would be subject to discussion among Allies of World War II, eventually it was not subject to any common ruling. Estimating the losses proved difficult, since many Soviet cultural institutions had no reliable catalogues, and the poorly developed art market in Russia made establishing market value of many Russian works of art virtually impossible. Additionally, once the Soviet forces entered non-Soviet territories, they quickly engaged in large-scale and poorly documented looting, while refusing to provide the lists of items removed from the Soviet occupation zone in Germany. The Bureau's own list was not finished until 1946, and even then it was highly incomplete.

In 1944 a Soviet counteroffensive on the Eastern Front succeeded in pushing German troops back, and Soviet troops began entering non-Soviet territories. On December 26, 1944, an official Soviet decree authorized soldiers to mail packages, monthly, from the front, with the weight varying according to rank (5 kg (11 lb) for rank-and-file soldiers, 10 kg (22 lb) for officers, and 15 kg (33 lb) for generals). It was inspired by a similar system introduced by the German army, and "was considered an open invitation to [Soviet] soldiers to seize what they could" and the beginning of the Soviet institutionalization of looting. This resulted in a significant increase of the packages sent by Soviet soldiers, which led to the overburdening of the official system. In turn, families of soldiers began to make requests of specific types of items (such as items of clothing) that they wanted to be "acquired". Soldiers also carried large packages when returning home; in extreme cases individual soldiers had declared "bags" weighting close to a ton.

Polish territories were among the first non-Soviet territories that the Red Army units entered. However, Polish authorities were generally not allowed to assume control over a town for several days after it was occupied by the Soviet forces, which was understood as a period of grace during which the Red Army soldiers were allowed to loot it. In some cases, looting and victory celebrations by the Red Army soldiers led to additional damage, for examples from fires (over 80% of the Polish town of Lubawa was damaged by a fire attributed to the drunk Red Army soldiers celebrating their capture of the town). Bogdan Musiał estimates that through large scale vandalism and arson, that "In pre-war East German territories, Red Army soldiers destroyed more cultural assets and works of art than they managed to confiscate and take to the USSR." Complaints by Polish communist authorities about looting by Soviet soldiers were often ignored by the relevant Soviet authorities; in extreme cases, this even led to violent clashes between Red Army soldiers and police forces operated by the Polish communists. The devastation and robberies became increasingly severe in territories Soviets considered to be German.

In February 1945, shortly after returning from the Yalta Conference Joseph Stalin issued several decrees outlining the principles and rules for the Soviet removal of cultural and industrial property from foreign territories controlled by the Red Army. They concerned not only German territories, but also other regions, such as Axis-aligned countries like Hungary, and also Allied countries, such as Poland or China (in territories captured from the Japanese, particularly in Manchuria). This led to institutionalized looting carried out by specialized groups operating on the orders of the Soviet government, the so-called Soviet "trophy brigades", composed of experts including art historians, museum officials, artists and restorers, tasked with finding objects of cultural value to be seized and sent to the USSR. Items seized were stored in places called "trophy warehouses". The brigades were operated by several agencies of the Soviet government; their coordination was poor and in some cases, they were described as competing with each other.

In addition to art, household and luxury items (clothing, furniture, vehicles), other major categories of items seized by the Soviets included scientific (see Russian Alsos), and, in particular, industrial equipment. Bank vaults were also emptied. Soviets dismantled and moved entire industrial plants, leaving empty walls. They also removed infrastructure elements, such as thousands of kilometers of train tracks. The first theater of operations for the trophy brigades, in February 1945, was the German part of Silesia and adjacent areas. Once stripped of items of interest to the Soviets, these would be handed over to Poland, as Recovered Territories. In a number of cases, the Soviets also looted areas which were part of the Second Polish Republic in the interwar period (for example, the towns of Września, Włocławek and Grudziądz). In other cases, the Soviet authorities, after initial looting of an industrial object, relinquished it to the Polish communist authorities for repair, then seized it again for another round of looting, before returning it again.