The film was shot in a Spanish mission from the 18th century, which is believed to be inhabited by at least 12 ghosts. During the shoot the script supervisor (Elisa Forni) could never use the Polaroid camera inside the mission: even though she used the flash all the photos turned out completely black. She had no problem taking the pictures outside. During a night take the first shooting day, the costume designer ('Sarah Fleming') saw a window unlatch and open on its own.
Claudia Soberón originally auditioned for the supporting role of Sor Luciana, but was given the main role of Angelica.
The original script title was "Cloisters". The title was changed during post-production. "Anima" means "Soul" in Latin.