Exposure to nature is widely considered to alter acute stress. Most research has focused on nature’s ability to facilitate stress recovery, while little is known about its effects on initial reactivity to a stressor and associated emotion regulation strategies. Guided by Nature-Based Biopsychosocial Resilience Theory, we investigated whether brief virtual nature exposure influences both stress reactivity and recovery, as well as stressor-specific appraisal and rumination. In a randomized controlled study, 164 healthy adults watched brief, two-dimensional virtual nature or indoor scenes either before or after an acute laboratory stress task. We repeatedly measured self-reported stress, salivary cortisol, heart rate, and heart rate variability to assess stress reactivity and recovery, alongside stressor-specific appraisal and rumination, and collected retrospective ratings of the environments’ perceived restorativeness and helpfulness in dealing with the stressor. Participants retrospectively rated nature videos as more restorative and helpful in managing and recovering from the stressor than indoor videos (moderate-to-large effects). In contrast, none of the registered hypotheses about the positive effects of nature videos on immediate overall stress responses, stress reactivity, stress recovery, appraisal, or rumination were significant. However, equivalence tests indicated that small-to-moderate effects cannot be ruled out. The results highlight a potential disconnect between participants’ retrospective perceptions of nature’s capacity to help cope with a stressor and their immediate psychological and physiological reactions. Although virtual nature may represent an easily implementable intervention, our findings encourage a critical reflection and calibration of expectations regarding the effectiveness of brief simulated nature exposures for reducing acute stress.