Richard Harris hated making the film so much that he refused to return to Hollywood for five years.
Average Shot Length = ~7 seconds. Median Shot Length = ~6.3 seconds.
Production had to be closed down several times due to Gary Cooper's frequent illnesses.
The task of bringing this novel to the screen was originally assigned to writer Ernest Lehman and director Alfred Hitchcock. Lehman eventually went to Hitchcock and told him that he couldn't come up with anything. Hitchcock told him not to worry about it, that they'd do something else. Lehman said, "But what about MGM?" Hitchcock replied "We won't tell them." That "something else" that they came up with was North by Northwest.