Stroessner, the son of a German immigrant, attended the Military College in Asunción and was commissioned in the Paraguayan army in 1932. He rose through the ranks to become general and in 1951 was made commander in chief of the armed forces. In 1954 he deposed President Federico Chávez (Chávez, Federico) and later assumed the presidency after an election in which he was the sole candidate for the office.

Stroessner attempted to placate the rural poor and urban labourers and at the same time supported the interests of the large landholders and businessmen. His administration stabilized the currency, moderated inflation, and provided some new schools, public health facilities, and roads; a large part of the national budget, however, was spent on the paramilitary forces necessary to preserve his authority. During Stroessner's presidency, Paraguay participated in the building of the massive Itaipú Dam along the Brazil-Paraguay border in 1975–82. Stroessner's supporters dominated the nation's legislature and courts and had the constitution modified in 1967 and 1977 to legitimize his six consecutive elections to the presidency. His administration actively participated in Operation Condor, a clandestine campaign coordinated by several South American rulers to eliminate their opponents. It was responsible for numerous extralegal arrests, extraditions, and other human rights abuses. In addition, Stroessner allowed Paraguay to serve as a refuge for a number of international fugitives, including Nazi war criminal Josef Mengele (Mengele, Josef).

Stroessner was elected to an eighth successive term as president in 1988 but was overthrown by a military coup in 1989. He thereupon went into exile in Brazil, where he was granted political asylum. In the early 21st century Paraguay unsuccessfully sought his extradition on charges relating to Operation Condor.