This was the official Canadian entry for the "Best Foreign Language Film" category at the 2005 Academy Awards, but it did not end up as one of the five foreign language films to be nominated.

Acquiring the music rights took such an important part of the budget, director and producer Jean-Marc Vallée had to cut his own salary.

It took Jean-Marc Vallée 10 years to write this film.

The music rights cost CND$600 000.

Even though the movie's dialogue is in French, for the theatrical release in France, subtitles were added for viewers who couldn't understand Québécois French.

Based on co-writer François Boulay's memories of growing up.

All of the cars driven by the father are Chrysler vehicles.

The movie title "C.R.A.Z.Y." has two references in the film. First, the famous hit song from singer Patsy Cline, which the father character, Gervais Beaulieu, is "crazy" about. Second, and more importantly, each letter represents the first letter of the five sons first names, in order from the oldest to the youngest (Christian, Raymond, Antoine, Zachary and Yvan). This fact, never revealed by the father, is discovered midway through the film by Zachary Beaulieu, and is seen during the end titles, by the viewers.

Jean-Marc Vallée: Director, Jean-Marc Vallée, plays the priest at the house after Raymond's funeral.