Virtual reality can facilitate experiments to examine the effects of landscape architectural design on site users. This study investigates the outcome of design interventions on a pedestrian’s perceived safety in an American urban alleyway environment. Participants (n=112) experienced either a baseline or designed 3D modeled alleyway followed by a survey. Findings show that the designed environment had a more significant effect on participants’ feelings of safety than the control environment, especially the design elements of lighting and planting. This study demonstrates the usefulness of virtual reality for assessing particular design outcomes through a human perspective.