After the February Revolution of 1917, the JSDLP Poale Zion was close to the left-wing Mensheviks (internationalists). In the fall of 1917, the JSDLP formed a bloc with them. In the spring–summer of 1917, the Party grew to 12–16 thousand people. Its representatives were part of the Ukrainian Central Rada and the Ukrainian Directory and participated in the creation of the Belarusian Rada.
Poale Zion condemned the October Revolution of 1917, advocated the transfer of power to the Constituent Assembly, but rejected the armed struggle against the Bolsheviks. In June 1918, the Poale Zionists were expelled from the Soviets at all levels, but in Soviet Russia, the party continued to operate legally. The Party experienced constant splits and factional struggle. Back in 1917, the Party split into two wings: the right (led by Solomon Goldelman) and the left (led by Grigory Fridlyand). In 1918, Secretary of the Party’s Central Committee Noe Baru headed the Poale Zionists.
In the Civil War environment, the JSDLP Poale Zion emphasized its opposition to the Bolsheviks but supported the Soviet government. Members of the Party participated in the fight against the interventionists, in particular, they were members of the Belarusian Insurgent Committee. In May 1919, the JSDLP Poale Zion announced that all members of the party up to the age of 30 were to join the Workers’ and Peasants’ Red Army, while the Poale Zionist leaders insisted on the formation of separate Jewish units within the Red Army. Soon, many Party members began to demand unconditional support for the Bolsheviks, which was largely due to the Jewish pogroms in the territories controlled by the Whites and the Ukrainian People’s Republic (UPR).
In 1919, the Party split. The right-wing group (Poale Zion UPR) collaborated with the Ukrainian Directory headed by Symon Petliura. In August 1919, at the conference in Gomel, the left-wing Poale Zionists established the Jewish Communist Party (JCP) Poale Zion. It actively promoted the idea of penetration into the Middle East through the structures of the Communist International (Comintern). In August 1920, the JCP Poale Zion and its related parties of other countries established the Global Jewish Communist Union Poale Zion (Communist Weltfarband), but later, under the pressure of the Russian Communist Party (Bolsheviks) – RCP(b), it had abandoned the Zionist ideology and declared its break with the Communist Weltfarband.
In December 1922, the JCP Poale Zion in the Soviet republics dissolved itself, some of its members joined the RCP(b). The last groups of Poale Zionists in the USSR ceased to exist in 1928. In Poland, the Poale Zionists continued their activities until 1951.