The cause was heart failure, said his son, Garo.
Argentina during the Falkland Islands war, to the Nicaraguan Contras and to Iraq during that country's war with Iran.
Soghanalian contended that many of those deals were aided or tacitly approved by the CIA.
During the early 1990s, Soghanalian served two years of a 6 1/2 -year federal prison sentence for conspiring to smuggle more than 100 combat helicopters to Saddam Hussein's military in Iraq. His sentence was reduced after he provided U.S. authorities with intelligence that helped break up a counterfeit ring.
Arrested several times, Soghanalian was generally released after judges learned that he was on official government business.
Fluent in five languages, he was once regarded as perhaps the world's most prolific weapons dealer, with seemingly unlimited access to tanks, missiles, helicopters and firearms of every description.
He was a Lebanese citizen and U.S. resident who believed strongly in America's causes and wanted to help, according to his son.
Of Armenian descent, Sarkis Garabet Soghanalian was born Feb. 6, 1929, in a part of Syria that is now Turkey. After his father died, he grew up in Beirut, where he began the arms-dealing career that made him a fortune.
In the 1990s, he moved to Miami Beach and lived in a palatial home on an island. With his son, Soghanalian operated an air cargo business at Miami International Airport.
He had homes around the world, including in Athens, Madrid, Paris and Amman, Jordan. He also owned a 136-acre farm in Wisconsin.
In 1958, he married an American who taught at a Beirut school. They lived in New York state for about 10 years before returning to Beirut and divorcing in the 1970s.
When asked in 2001 by a "Frontline" producer how closely he had worked with the U.S. government while arranging weapons sales to Argentina during the Falklands war, Soghanalian replied: "The Americans knew what I was doing every minute, every hour."
In addition to his son, Garo, he is survived by his daughter, Melo; three grandchildren, four great-grandchildren; a sister and a brother.