Mosaffa's experience with directing began with the short films, Incubus, The Neighbour and the documentary feature, Farib-e-She'r or The Deceit of Poesy. He then directed his first film in 2005 with Sima-ye Zani Dar Doordast (a.k.a. Portrait of a Lady Far Away), starring Leila Hatami and Homayoun Ershadi. The film was shortlisted for the Sutherland Trophy, awarded to the Director of the most original first feature film screened at The Times BFI London Film Festival. His first feature film subsequently won the People's Choice Award at the Chicago International Film Festival and was nominated for the Crystal Globe at the 2005 Karlovy Vary International Film Festival. Mosaffa's second film, The Last Step /Pele ye Akhar, starring Leila Hatami has received acclaim from critics and audiences worldwide following its international premiere at the 2012 Karlovy Vary International Film Festival which gained Mosaffa the international critics' FIPRESCI prize for best film and awarded Leila Hatami with the Crystal Globe for Best Actress for her leading role in the film.