After graduation he wrote and directed a number of acclaimed short films, including the short film comedy Elixir (2004), which he was awarded the Bo Widerberg scholarship. In 2010, he made his directorial debut with the film Sebbe, which won a Guldbagge Award for Best Film, and earned him a nomination as best Director at the 46th Guldbagge Awards. At the 60th Berlin International Film Festival, the film was competing in the Generation 14Plus category, for which Najafi won the award for Best First Feature. In 2012, he directed Easy Money II: Hard to Kill, the sequel to the 2010 film Easy Money.