Mostows theatrical film debut was as writer and director of the critically acclaimed 1997 Paramount thriller Breakdown, starring Kurt Russell and Kathleen Quinlan. The same year, he executive produced The Game, starring Michael Douglas and Sean Penn. Both films opened at #1 at the box office.

In 1998, Mostow directed Tom Hanks in La Voyage Dans La Lune, the finale episode of the Emmy Award-winning HBO mini-series From the Earth to the Moon.

Mostow is partnered with producer Hal Lieberman in Mostow/Lieberman Productions. Based at Universal Studios, the company is in development on a number of feature and television projects.

Mostow began his filmmaking career as a student at Harvard University, where he directed numerous award-winning shorts and documentaries. His 1991 feature-length directorial debut, the Showtime television thriller Flight of the Black Angel, earned him a CableACE nomination for Best International Movie or Special.