In 1938 the party merged with the Workers' Party to become the Bulgarian Workers Party. In 1948 the BWP merged with the Bulgarian Workers' Social Democratic Party to become the Bulgarian Communist Party once again.
Following Dimitrov's sudden death, the party was led by Vulko Chervenkov, a hard-line Stalinist who oversaw a number of party purges under Moscow's guidance. The party joined the Cominform at its inception in 1948 and conducted purges against suspected Titoites following the expulsion of the Communist Party of Yugoslavia from the alliance. Thousands of suspect party members and suspected counterrevolutionaries outside of the party were imprisoned. In March 1954, one year after Stalin's death, Chervenkov was deposed.
From 1954 until 1989 the party was led by Todor Zhivkov, who was staunchly supportive of the Soviet Union and remained close to its leadership after Nikita Khrushchev was deposed by Leonid Brezhnev. The demands for reform which swept Eastern Europe in 1989 forced Zhivkov's resignation and the party moved in a more moderate direction, abandoning Marxism-Leninism in 1990 and renaming itself the Bulgarian Socialist Party (BSP).
A number of old Communists established several splinter parties with an insignificant number of members. One of these parties named Communist Party of Bulgaria (Komunisticeska Partija na Balgarija) is nowadays a party led by Alexander Paunov. It is part of the Coalition for Bulgaria, an alliance led by the Bulgarian Socialist Party. The coalition won in the 2001 elections 17.1% of the popular vote and 48 out of 240 seats. At the last legislative elections, held on 25 June 2005, the Coalition won 34.2% of the popular vote and 82 out of 240 seats.