Pereira's first major government job was chief of telecommunications in Guinea-Bissau. From the late 1940s until Cape Verde's independence, Pereira was heavily involved in the anti-colonial movement, organizing strikes and rising through the hierarchy of his party, the Partido Africano da Independencia da Guiné e Cabo Verde.
Although Pereira initially promised to lead a democratic nation upon becoming president, he compounded the country's chronic poverty by crushing dissent following the overthrow of Luís de Almeida Cabral. Cabral was the president of Guinea-Bissau and Pereira's former ally.
The country's policies during Pereira's rule tended toward Cold War nonalignment and basic reforms to help the peasantry. He controversially allied his country with socialist dictatorships in China and Libya.
Pereira lost democratic elections in 1991 to António Mascarenhas Monteiro.
See also: List of Presidents of Cape Verde