Director Álex de la Iglesia considered casting Fernando Esteso as Nino and Andrés Pajares as Bruno.
The principal theme of the soundtrack is based on Los pekenikes's song Embustero y bailarín (Liar and dancer).
Bruno and Nino drive the exact same model of Mercedes, and their license plates are consecutive.
Sixto Cid (aka Sixto 'Piti' Cid), who plays Fakir, appears in credits by a mistake as Cid, and his character as Fakir Sixto 'Piti'.
According with Santiago Segura, in the first takes that they filmed in which Bruno slaps Nino, El Gran Wyoming slapped him so soft trying to not hurt him, that the takes weren't valid, and they had to repeat them. In consequence, Segura was softly slapped several times, and was himself who insisted Wyoming for slap him hard.