They say "the island" many times but they don't say its name. It is in fact, the tiny island of Formentera.
Some of the most sexual explicit content was made by doubles, not by the main actors.
The movie is divided in two chapters: "Lucía" and "El Sexo" which gives its title to the movie.
Julio Medem took his story through eight drafts, and spent five months in rehearsals.
Ana Risueño was initially cast as Lucía. Yet Julio Medem later claimed she did not resemble his idea of the character. In her place came Paz Vega, who was seven years younger than Risueño, and performed a disastrous four-hour read-through of the entire script that only confirmed Medem's perversely stubborn belief that she was Lucía because of the appropriate way she had struggled with the character as defined by himself through Lorenzo.