Despite 3D TVs and applications gaining popularity in recent years, 3D displays on mobile devices are rare. With low-cost head tracking solutions and first user interfaces available on smartphones [1], the question arises how effective the 3D impression through motion-parallax is and whether it is possible to achieve viable depth perception without binocular stereo cues. As motion parallax and stereopsis may be considered the most important depth cues [3], we developed an experiment comparing the user's depth perception utilizing head tracking with and without stereopsis.