The PPP was founded on 1 January 1950, and was the first mass party in the country.  It was initially a multi-ethnic party began as the Political Affairs Committee (PAC) in 1946 and was supported by workers and intellectuals.  The party held its First Congress on 1 April 1951.  Its Third Congress, at which Burnham unsuccessfully sought to become party leader, was held in March 1953. 

The PPP went onto win the 1953 general elections with 18 of the 24 seats in the new House of Assembly and Cheddi Jagan became Prime Minister.  However, Jagan's radical social reforms led to the British authorities sending in troops, claiming there was the threat of a Marxist revolution.  After the PPP won the 1957 elections, Burnham's moderate faction left the party to establish the Afro-Guyanese dominated People's National Congress, establishing an ethnic divide between the two parties, with the PPP left representing Indo-Guyanese.  The PPP won the 1961 elections by a 1.6% margin, but received almost double the number of seats, leading to serious inter-racial violence. 

The party lost office in the 1964 elections.  Despite winning the most seats, the PNC was able to form a coalition government with The United Force.  Following an outright PNC victory in the 1968 elections, the PPP remained in opposition during a series of fraudulent elections in the 1970s and 1980s.  It finally returned to power in the 1992 elections.  It retained power in elections in 1997, 2001 and 2006.