Nerea Camacho was hesitant about cutting her hair for her role, but finally accepted, crying in the process. Javier Fesser, thanking her courage, cut his hair as well.
"Camino" (Spanish for "way") is also the title of the foundational book of Opus Dei (the religious institution portrayed in the film), written in 1934 by Josemaría Escrivá de Balaguer.
Claimed to be based on the story of Alexia Gonzalez - Barros. The family has not accepted any of the details depicted in the movie though.