Moore is best known for his films "Sicko," "Fahrenheit 9/11," "Bowling for Columbine" and "Roger and Me."
His latest documentary follows his trek across the United States, during which he encouraged young people to vote in the 2004 presidential election.
The BBC said he is offering the film for free to North Americans for three weeks, starting Sept. 23, as a means of celebrating his 20 years in the film industry and reminding people to vote in the November 2008 presidential election.
"This is being done entirely as a gift to my fans," the BBC quoted Moore as saying.
Scarlett Johansson steps out with fiance after pregnancy reveal
Interpol investigating stolen passports on missing flight