Navigation systems are popular, as they support navigators in their everyday wayfinding activities. However, what happens to spatial knowledge acquisition and retention with increasing reliance on navigation system support? We conducted an outdoor wayfinding study with pedestrians, supported by the eye tracking data collection method, to investigate the role of navigation assistance on spatial knowledge acquisition. We specifically studied visual interactions with the environment between aided and unaided wayfinders. We observe that navigation system use significantly reduces forward and backwards glances during navigation, while glances to the right and left of the navigator along the route do not differ when comparing aided and unaided wayfinders. Our empirical findings shed new light on how the reliance of navigation assistance during way finding may affect navigators’ engagement with the traversed environment, and how this in turn may affect spatial knowledge acquisition during wayfinding.