In this study the effects of locomotion techniques were investigated in virtual worlds made for phobia treatment. Three locomotion techniques walk-in-place and hand-controlled viewing and gaze-directed steering were systematically varied for several taks in different virtual worlds. A series of variables were measured to show the effects on presence and fear and avoidance and and simulator sickness. In the experiment was found that more natural locomotion techniques contribute to higher levels of presence and fear. This researh provides guidelines to improve the usability of systems for virtual reality exposure therapy.