In Haiti, Prosper Avril is ousted eighteen months after seizing power in a coup d'état in September 1988.

Haiti, officially the Republic of Haiti, is a country in the Caribbean on the island of Hispaniola in the Caribbean Sea, east of Cuba and Jamaica, and south of the Bahamas. It occupies the western three-eighths of the island, which it shares with the Dominican Republic. Haiti is the third largest country in the Caribbean, and with an estimated population of 11.4 million, is the most populous Caribbean country. The capital and largest city is Port-au-Prince.

Matthieu Prosper Avril is a Haitian political figure who was President of Haiti from 1988 to 1990. A trusted member of François Duvalier's Presidential Guard and adviser to Jean-Claude Duvalier, Lt. Gen. Avril led the September 1988 Haitian coup d'état against a transition military government installed after Jean-Claude Duvalier's 1986 overthrow. He was President until March 1990, in a period which according to Amnesty International was "marred by serious human rights violations". He was arrested in 2001, but released in March 2004 after the 2004 Haitian coup d'état overthrew Jean-Bertrand Aristide.

A coup d'état, or simply a coup, is typically an illegal and overt attempt by a military organization or other government elites to unseat an incumbent leadership. A self-coup is said to take place when a leader, having come to power through legal means, tries to stay in power through illegal means.

The September 1988 Haitian coup d'état took place on 18 September 1988, when a group of non-commissioned officers in the Haitian Presidential Guard overthrew General Henri Namphy and brought General Prosper Avril to power. Namphy had been a member of the National Council of Government from 1986 until the February 1988 inauguration of Leslie Manigat, who had won the military-controlled 1988 general election. Namphy had overthrown Manigat in the June 1988 coup d'état when Manigat sought to exercise his constitutional right to control military assignments.