After making his big-screen debut in 2004's romantic comedy The Ski Trip, Sleiman landed his first major role in the reality show satire American Dreamz co-starring Dennis Quaid and Hugh Grant. A string of small roles quickly followed, including that of an American solider on "ER," an Islamic peacemaker on "NCIS" and a terrorist suspect on "24."

In 2007, Sleiman appeared in the sports drama Futbaal: The Price of Dreams and the Thomas McCarthy-helmed The Visitor. For the latter film -- in which he plays an illegal immigrant living in a college professor's New York apartment -- Sleiman received an Independent Spirit Award nod.