Despite being purposefully designed and strategically placed in buildings to facilitate efficient evacuation, emergency exit doors are frequently underutilized during evacuations. To address this issue, this study explores why individuals often fail to use emergency exit doors during evacuations via a virtual reality and eye-tracking experimental study and investigates human emergency wayfinding behaviors through the lens of perceptions and attention. The results show that individuals’ attention to wayfinding clues is positively related to their exit choices. Failure to notice an emergency exit door is a key contributor to explaining how familiarity affects the usage of the emergency exit door. Participants in the familiarity group were less likely to pay attention to the exit door and thus rarely use it. However, when participants had fixations on the door, their exit choices were not significantly different between the familiarity and unfamiliarity groups. In the present experiment, door color and type did not have a significant impact on participants’ visual attention and exit choices. Specifically, the effect of door type on participants’ exit choices was impaired by the presence of the stairwell sign. The experimental results reveal the conspicuity and visibility of exit doors and explicit and clear wayfinding information are crucial to increasing their usage during indoor evacuations.