The League of Communists of Serbia was the Serbian branch of the League of Communists of Yugoslavia, the sole legal party of Yugoslavia from 1945 to 1990. Under a new constitution ratified in 1974, greater power was devolved to the various republic level branches. In the late 1980s, the party was taken over by a faction endorsing Slobodan Milosevic to become leader of the party. Milosevic appeased nationalists in Serbia by promising to reduce the level of autonomy within the autonomous provinces of Kosovo and Vojvodina. This policy increased ethnic tensions with the other republics and nationalities. During the early 1990s, the growing ethnic tensions between the republics of Yugoslavia led to the breakup of the federal party.
On July 27, 1990, it merged with several smaller parties to form the Socialist Party of Serbia.