The scenes with Oliver walking alone through a snowy New York were added after principal photography was completed. The production was almost out of money and did not have the necessary funds for permits to shoot in New York City again - so all the shots were grabbed "illegally" using a skeleton film crew and Ryan O'Neal.
Author Erich Segal wrote the screenplay first, then adapted it into a novel, which was published before the film's release and became a runaway bestseller.
Film debut of Tommy Lee Jones, an actual Harvard graduate. Writer Erich Segal based Ryan O'Neal's character on Jones, and on his Harvard roommate, future Vice-President Al Gore.
The most famous line from the film, "Love means never having to say you're sorry", was actually misspoken from the script. Originally the line was supposed to be: "Love means not ever having to say you're sorry."
Eight up-and-coming actors including Michael Douglas, Jon Voight and Peter Fonda turned down the role of Oliver, despite being offered 10% of the gross.
The first television showing on this film, on ABC-TV in 1972, marked the shortest time span up to then between a film's theatrical release and first showing on television.
John Wayne refused to believe that Love Story (1970) "sold because the girl went around saying 'shit' all the way through it." Instead he believed that "the American public wanted to see a little romantic story."
Both the Cornell and Dartmouth hockey teams were played by Dartmouth's actual team. Cornell hockey coach Ned Harkness only allowed Cornell jerseys to be used in the film on the condition that Cornell win the game with Harvard.
Incoming freshmen at Harvard University, where the movie takes place, are traditionally shown a screening of the film at which they indulge in ritualized mass heckling.
Old-fashioned gas lights and lamp posts out of Boston's long past, from places like Beacon Hill, were added to scenes in Harvard Yard to make it look more like the producer's image of Harvard. Ryan O'Neal ruined several takes by tripping over the chains holding them in place.
Original director Larry Peerce, who had directed Ali Macgraw in her debut " Goodbye Columbus ", left the movie during pre-production, and Arthur Hiller came on board for $250,000 plus 25% of the net. According to Peter Bart, who was then a young Paramount executive, this earned Hiller a further $5m.