The party was represented at the 6th Congress of the Communist International in 1928 by Fu'ad al-Shimali. Under the French Mandate it was an underground organization, then legalized in 1936–1939 by the French Front Populaire government, and again in 1941. The party took a new option of collaboration with the nationalist movement and playing down its socialist themes in 1936, in accordance with the 7th Congress of the Communist International in 1935.
Later the party was divided into the Syrian Communist Party and the Lebanese Communist Party, but the decision, taken at the end of 1943, was only implemented in 1964. In between, common central committee and political bureau were maintained.