At the extraordinary party conference of the SED in December 1989, the party renamed itself SED/PDS. The new name was intended to document the renewal and reform process which was initiated at the same time. At the following party conference in February of 1990, a further renaming to PDS took place without however effecting a resolute break with the predecessor party. The Berlin solicitor Gregor Gysi was elected Chairman of the party. At the elections to the People's Chamber in March 1990, the PDS with its main candidate Hans Modrow received 16.3% of the votes.
At the first all-German elections, the PDS received 2.4% of the votes (11% in the East). Due to a special East-West regulation, the PDS entered Parliament with 17 members although they had failed to gain the threshold figure of 5%. At the elections to the Lower House of Parliament in 1994, the party received 4.4% of the votes and was allocated 30 seats in the Lower House of Parliament, due to 4 direct mandates. In 1998, the party managed to gain 5.1% of the votes and was allocated 37 seats in the Lower House of Parliament.
In the years 1998/99, the party gained considerable votes in the elections to the Federal Parliaments in the New Federal States and often achieved better results than the CDU or the SDP with the result that it is in power in government coalition with the SPD in Mecklenburg-Vorpommern and is tolerating a minority government of the SPD in Sachsen-Anhalt.