The Pidjiguiti massacre (also spelled Pijiguiti) was an incident that took place on 3 August 1959 at the Port of Bissau's Pijiguiti docks in Bissau, Portuguese Guinea. Dock workers went on strike, seeking higher pay, but a manager called the PIDE, the Portuguese state police, who fired into the crowd, killing at least 25 people. The government blamed the revolutionary group African Party for the Independence of Guinea and Cape Verde (PAIGC), arresting several of its members. The incident caused PAIGC to abandon their campaign of nonviolent resistance, leading to the Guinea-Bissau War of Independence in 1963.

The International and State Defense Police (Portuguese: Polícia Internacional e de Defesa do Estado; PIDE) was a Portuguese security agency that existed during the Estado Novo regime of António de Oliveira Salazar. Formally, the main roles of the PIDE were the border, immigration and emigration control and internal and external State security. Over time, it came to be known for its secret police activities.

The agency that would later become the PIDE was established by the Decree-Law 22992 of August 1933, as the State Surveillance and Defense Police (Polícia de Vigilância e Defesa do Estado) or PVDE. It resulted from the merger of two former agencies, the Portuguese International Police and the Political and Social Defense Police.

PVDE was founded by Captain Agostinho Lourenço, who in 1956 would become the President of Interpol.

The PVDE was transformed into the PIDE in 1945. PIDE was itself transformed into the Directorate-General of Security or DGS in 1968. After the 25 April 1974 Carnation Revolution, DGS was disbanded in Portugal, but continued to exist transitionally in the Portuguese overseas territories as the Military Information Police or PIM, being finally completely disbanded in 1975.

Although the acronym PIDE was only formally used from 1945 to 1969, the set of successive secret polices that existed during the 40 years of the Estado Novo regime are commonly referred to as the PIDE. Historically, this set of police agencies is also often referred as PIDE/DGS, from the acronyms of its two last designations. It is referred to in this last way in article 293 of the Portuguese Constitution, which states its criminalization and judgment of its former officers.

During its existence, the organization was known for its actions during the Spanish Civil War, its role as a political police, its counter-espionage activities during World War II and its counter-insurgency operations in the Portuguese Colonial War.