The three lead actors all died in 2005.
Hugo Butler, a victim of the blacklist, only received credit for his screenplay in 1997, 29 years after his death.
The producers of the film wanted Luis Buñuel to use Orson Welles for the role, with Buñuel refusing, saying he was too loud and too fat. They arranged a screening of Welles' Macbeth (1948) to show how a bearded Welles would look, but Buñuel demanded Dan O'Herlihy, who played Macduff in that film, for the lead role.
Exterior shots were filmed near the city of Manzanillo in the Mexican state of Colima. There were 60 people in the production crew. The crew took daily doses of Diodoquin and aralen to guard against dysentery and malaria, respectively. A security squad of local Manzanillans kept snakes, wild boar, and other dangerous animals at bay with guns and machetes.