The naval forces of Paraguay were developed under Francia. The Navy was expanded in the period of the President Lopezes and included both naval artillery and a marine battalion element.

The Paraguayan Navy played an important role in the early part of the Triple Alliance War. In 1865, the Paraguayan naval forces helped in capturing the Argentina city using the steam warship Tacuari and then battled with the Brazilian fleet in which they lost in first attempt and then regained the control of the city. After forcing the fleet of Brazil to withdraw to Riachuelo, the naval force once again attacked in one of the major riverine naval engagements.

For 50 years, following the end of the occupation by the forces of Brazil in 1876, the naval forces remained very small. In response to Bolivia tensions, it was upgraded by acquiring small air arms in 1929 and some new vessels in 1931. The role of the fleet in the Chaco War was limited to carrying troops and supplies to the Chaco and supplying antiaircraft cover for the army. Some officers of the naval force also served as a ground force commanders. Air arm of the naval forces also carried out important exploration, support missions.

After the Chaco War, the naval inventory grew slowly; patrol boats were the chief acquisitions donated by U.S. in 1944. The donations by Argentina and United States in the 1950s benefited the naval aviation arm. The fleet was enlarged in 1960s and 1970s with 3 U.S. manufactured minesweepers which were acquired from Argentina. In the same period, U.S. transferred a variety of crafts to Paraguay which included landing craft, support vessels, launches and tugs. These were purchased during the 1975-77 period. During the 1980s, a Brazilian-built river gunboat was the only major acquisition which was commissioned is 1985.

The naval force also has the responsibility of guarding the coast, which maintained navigational aids and also guarded the major river crossings. After training in Asuncion, the officers of the navy, were sent on Argentine fleet vessels and in Argentine naval schools in Argentina for advanced training.

Today’s Paraguayan navy has 17 patrol boats, 13 of which were built locally and 4 were donated by USA and Taiwan. The core assets have two attack helicopters and the Aeschylu AS-350. It also has 6 training and liaison Cessna planes.