Based on the memoir of the same name by Raimond Gaita, the film tells the story of Romulus (Eric Bana) and his wife Christine (Franka Potente), and their struggle in the face of great adversity to raise their son, Raimond, played by the nine-year-old Kodi Smit-McPhee.

The film tells the story of Romulus Gaiţă, a Yugoslavian immigrant to Australia after World War II and his struggle to bring up his son, Raimond, in an isolated shack in the Victorian bush.

Roxburgh wanted to make a film straight after reading the book, Romulus, My Father, given to him by his sister.

Gaita had had several offers soon after the publication of the book, but had turned them down "because it's very hard to make a film about people with mental illness without being kitschy or in some way offensive".

Gaita said finding nine-year-old Kodi Smit-McPhee to play the young Raimond was a turning point because he "miraculously captured exactly as I felt".