Chuck Roberson (John Wayne's longtime stuntman) was meant to double for Jim Brown on some of the riskier stunts, with director Tom Gries planning to put black-face on him. Burt Reynolds would not perform with him, deeming it improper, and stated "Those days are gone, you better get a black stuntman here right now." When the production manager stated it was not in the budget, and "Fox would never go for it," Reynolds paid $500 out of his own pocket to pay for a black stuntman.
Burt Reynolds and Raquel Welch had a falling out while making this movie. Three years later, they both starred in Fuzz (1972). However, Welch only agreed to do the movie after it was agreed that she would not have to appear in any scenes with Reynolds. They would remain enemies until 1982 when the producers of Cannery Row (1982) fired Welch, claiming she was unprofessional, and replaced her with Debra Winger. Reynolds testified on her behalf stating "Although Raquel and I don't like each other, she was always on time, well-prepared, and thoroughly professional." She ended up winning $10.8 million.
The producers wanted Raquel Welch to shower under the water-tower sans shirt. "It was just one more way of trying to get Rocky nude", Welch later said. She defied the producers and kept her shirt on. Years later, Burt Reynolds commented, "It was twice as sexy the way she did it."
While filming the fight on the cliff-top, Jim Brown mentioned to Burt Reynolds that he wasn't too keen on being so close to the edge of a serious drop. Reynolds replied, "If we fall, the newspapers will say 'Jim Brown and unknown actor die.'"
According to Fernando Lamas' wife memoirs - Esther Williams' biography - during the shooting of this movie, Jim Brown defied Lamas to fist fight with him, for fun, so that Brown could prove his physical superiority, but everything went awry for Brown, because Lamas was a karate expert.