The Guinea-Bissau War of Independence, or the Bissau-Guinean War of Independence, was an armed independence conflict that took place in Portuguese Guinea from 1963 to 1974. It was fought between Portugal and the African Party for the Independence of Guinea and Cape Verde, an armed independence movement backed by Cuba, the Soviet Union, and Yugoslavia. The war is commonly referred to as "Portugal's Vietnam" because it was a protracted guerrilla war which had extremely high costs in men and materiel and which created significant internal political turmoil in Portugal.

The African Party for the Independence of Guinea and Cape Verde is a political party in Guinea-Bissau. Originally formed to peacefully campaign for independence from Portugal, the party turned to armed conflict in the 1960s and was one of the belligerents in the Guinea-Bissau War of Independence. Towards the end of the war, the party established a socialist one-party state, which remained intact until multi-party democracy was introduced in the early 1990s. Although the party won the first multi-party elections in 1994, it was removed from power in the 1999–2000 elections. However, it returned to office after winning parliamentary elections in 2004 and presidential elections in 2005, since which it has remained the largest party in the National People's Assembly.