He was 76.
Wilson died at Memorial Medical Centre-Lufkin after having difficulty breathing after attending a meeting in the eastern Texas town where he lived, said hospital spokeswoman Yana Ogletree.
Wilson was pronounced dead on arrival, and the preliminary cause of death was cardiopulmonary arrest, she said.
Wilson represented Texas' 2nd Congressional District in the US House from 1973 to 1996 and was known in Washington as "Good Time Charlie" for his reputation as a hard-drinking womaniser.
He once called former congresswoman Pat Schroeder "Babycakes," and tried to take a beauty queen with him on a government trip to Afghanistan.
Wilson, a Democrat, was considered both a progressive and a defence hawk. While his efforts to arm the mujahedeen in the 1980s were a success - spurring a victory that helped speed the downfall of the Soviet Union - he was unable to keep the money flowing after the Soviets left.
Afghanistan plunged into chaos, creating an opening eventually filled by the Taliban, which harbored al-Qaida terrorists. After the September 11, 2001 terror attacks - carried out by al-Qaida terrorists trained in Afghanistan - the US ended up invading the country it had once helped liberate.
"People like me didn't fulfill our responsibilities once the war was over," Wilson said in a September 2001 interview with The Associated Press. "We allowed this vacuum to occur in Afghanistan and Pakistan, which enraged a lot of people. That was as much my fault as it was a lot of others."
His efforts to help the Afghan rebels - as well as his partying ways - were portrayed in the movie and book Charlie Wilson's War.
In an interview after the book was published in 2003, he said he wasn't worried about details of his wild side being portrayed.
"I would remind you that I was not married at the time. I'm in a different place than I was in at the time and I don't apologise about that."
Wilson said. US Defence Secretary Robert Gates said that when he was at the CIA he knew Wilson, whom Gates said "was working tirelessly on behalf of the Afghan resistance fighting the Soviets." "
As the world now knows, his efforts and exploits helped repel an invader, liberate a people, and bring the Cold War to a close.
After the Soviets left, Charlie kept fighting for the Afghan people and warned against abandoning that traumatised country to its fate - a warning we should have heeded then, and should remember today," Gates said in a written statement.
Charles Nesbitt Wilson was born June 1, 1933, in Trinity. He attended Sam Houston State University in Huntsville before earning his bachelor's degree from the US Naval Academy in 1956.
Wilson served as a Naval lieutenant between 1956-60, then entered politics by volunteering for John F. Kennedy's presidential campaign.
He served in the Texas House and then in the Texas Senate before being elected to the US House in 1972.
As a member of the House Appropriations Committee, Wilson helped secure money for weapons and worked with then-CIA agents Gust L. Avrakotos and Mike Vickers to get them to the mujahedeen.
The Soviets spent a decade battling the rebels before pulling the Red Army from Afghanistan in 1989. Two years later, its economy in ruins, the Soviet Union fell apart.
Vickers, now assistant secretary of defence for special operations, said that Wilson was a "great American patriot who played a pivotal role in a world-changing event - the defeat of the Red Army in Afghanistan, which led to the collapse of communism and the Soviet empire."
Long-time friend Buddy Temple, who was with Wilson when he collapsed, said that despite Wilson's reputation as a playboy, he was serious about representing east Texas, including helping to create the Big Thicket National Preserve - almost 40,470ha of swamps, bogs and forests.
"Charlie was a giant. We have lost a giant. There won't be another like him," Temple said at a hospital news conference announcing Wilson's death.
Wilson left politics in 1996, after he no longer found it any fun. He lobbied for a number of years before returning to Texas.
In 2007, he had a heart transplant after being diagnosed with cardiomyopathy, a disease that causes an enlarged and weakened heart.
Schnabel said he had just been with Wilson a few weeks ago for the dedication of the Charlie Wilson chair for Pakistan studies at the University of Texas, Austin, a $US1 million ($NZ1.43m) endowment.
He said Wilson had been doing "very good" and said his former boss described himself as "a poster boy" for heart transplants.
Ogletree said Wilson is survived by his wife, Barbara, whom he married in 1999, and a sister.
