Filming began in 2000 but was halted due to financing issues in January 2001, with fifteen shooting days still remaining. Director Ivan Fíla finished a rough cut of the footage already shot, which he showed to potential backers in hopes of gaining financing to complete the film. In 2003, producer Rudolph Biermann saw the footage and helped finance the completion of the film.
Casting the role of Barbu took two years, during which time director Ivan Fíla auditioned over three hundred boys in several countries throughout Europe before finally finding Iakov Kultiasov at a circus school in Saint Petersburg.
Before filming began, Iakov Kultiasov and Julia Khanverdieva, who play Barbu and Mimma, respectively, trained for a year with a circus teacher in Prague in order to learn the specific circus skills required for their roles.
When filming began in 2000, actor Iakov Kultiasov was eight years old. When filming was finally completed in 2003, he was twelve. During the three year break in filming, he did not grow. He later told director Ivan Fíla, "I promised to myself not to grow unless we finish the film."
Writer/director Ivan Fíla first conceived the idea for the film in 1992 in Milan, Italy, where he met street kids stealing from tourists. To research the film, he visited some of the camps where the kids were living and talked to them. The film is based on many of these kids' real life stories.