The word 'yeyo' is used by Tony Montana (Al Pacino) as a slang word for cocaine. This word was not in the script, and was ad-libbed by Pacino during the first drug deal scene (chainsaw scene), and Brian De Palma liked it enough to keep using it throughout the film. Pacino learned the word while learning the Cuban accent.
The cocaine used throughout the shooting of the film was supposed to be dried milk, but that couldn't be used because it didn't fit well when the scene was shot. Director Brian De Palma refuses to admit what substance was ultimately used for cocaine out of fear that it would destroy the illusion of realism.
During rehearsals for a gunfight, Pacino was injured after he grabbed the barrel of a prop gun which had just been used to fire several dummy bullets. His hand stuck to the hot barrel and he was unable to remove it immediately; the injury sidelined him for 2 weeks.
Scarface: al pacino & michelle pfeiffer
Oscars & Globes