centrist Brazilian Christian Democratic political party.

The Party of the Brazilian Democratic Movement (PMDB) was founded in 1980 by members of the Brazilian Democratic Movement, which had been created in the mid-1960s as the official opposition to the military government but had dissolved in 1979. The PMDB, which endorsed democratization and the return of civilian rule, originated as a moderate leftist party, but it soon began to attract widespread support, particularly by moderating its policies and merging with the centre-right Popular Party. In 1985 the PMDB joined with the Liberal Front Party and other groups in Brazil's first civilian elections since 1964 to support the election of Tancredo de Almeida Neves as president and of José Sarney as vice president. (Sarney was inaugurated as president after Neves died before his term of office was to begin.)

By 1986 the PMDB was Brazil's largest party, winning control of both houses of the national legislature and 22 of 23 state governorships. Subsequently, however, internal dissension between the party's moderate and leftist elements deepened, particularly over Sarney's support for maintaining Brazil's presidential form of government, and in 1988 a number of leftists split to form the Brazilian Social Democratic Party (Partido da Social Democracia Brasileira; PSDB). Nonetheless, the PMDB continued to show strength in congressional elections, winning pluralities in both houses in the 1990 and the 1994 elections. It also enjoyed success in many state elections. The PMDB was a key component of the electoral coalition of PSDB presidential candidate Fernando Henrique Cardoso (Cardoso, Fernando Henrique), who was elected president in 1994 and reelected in 1998. Throughout Cardoso's term, the PMDB generally backed his policies, but despite its large number of deputies, it was hampered by a lack of policy coherence and by weak leadership, and in 2002 it decided against running a presidential candidate and in favour of backing the PSDB's candidate.

Although the PMDB initially attracted strong support in wealthy areas and in the cities, it now is strongest in rural areas and among the poor.