The 28th Congress of the CPSU (July 2, 1990 – July 13, 1990) was held in Moscow. It was held a year ahead of the traditional schedule and turned out to be the last Communist Party of the Soviet Union (CPSU) congress in the history of the party.
- Mikhail Gorbachev was reelected General Secretary (by a 3411 to 501 vote); Vladimir Ivashko was elected his deputy.
- A new Party Statute was passed, which formalized the end of the monopoly of power of the CPSU announced at the previous Party Congress.
- The New Union Treaty project was proposed by Gorbachev.
- Boris Yeltsin and some others resigned from the party after the "CPSU Democratic Platform" group failed to advance the transition to a parliamentary structure of the organization, while the "Marxist Platform" failed to oppose Gorbachev's reforms of "healing socialism by capitalism".
- The congress failed to issue the next Program, and issued only a Program Declaration.
The first Plenum of the new CPSU Central Committee was held July 13–14, and with the exception of Gorbachev, a completely new Politburo was elected.
Various organizations claiming to be the successor of the CPSU have held congresses continuing the numbering established by the CPSU and its predecessors. The Communist Party of the Soviet Union (1992) held its so-called XXIXth Restorative CPSU Congress in 1992 declaring the CPSU reinstated. Similarly, the Union of Communist Parties — Communist Party of the Soviet Union, established in 1993, has also held congresses starting from XXIX, the most recent being the XXXIIIrd Congress.