When Katharine Hepburn filmed the scene where she falls into the canal, one of her eyes became infected. That infection stayed with her for the rest of her life.
Having cast Isa Miranda as the older widowed concierge of the hotel, director Sir David Lean was upset to find that she had recently had a facelift and looked too young for the part. Since recasting at that late stage was out of the question, Lean went with it.
The number of tourists travelling to Venice doubled after this movie's release.
Once the script was in hand, the cast and crew made its way to Venice to begin prepping the locations. Sir David Lean had accepted the job of directing it in part because of a desire to no longer do soundstage work but work on locations outside. He remarked that working on a soundstage made it feel as though one was working in a "pitch-black mine . . . I prefer the sun." He set out about Venice, picking out locations and taking pictures. Lean would fall in love with Venice and later live there part of every year.