||This study utilized a quasi-experimental, within-subjects design to explore the effects of a 5-day nature immersion on perceived mindfulness, behavioral performance, and brain wave activity using Electroencephalography (EEG) to assess the amplitude of the P3a and P3b Event-Related Brain Potentials. Participants were tested in three separate sessions, a pre-test about two weeks before the nature exposure to determine baseline levels, a desert test to see if any significant changes occurred due to the nature exposure, and a post-test roughly two weeks after the nature exposure. Twenty-six participants were tested. In each session, participants completed a three-stimulus oddball task as well as a self-report mindfulness scale. Repeated-measures ANOVAs were used to analyze differences between sessions. Perceived mindfulness increased during exposure to nature (F(2, 73) = 5.231, p = 0.007), but no other changes were significant. Correlational analyses found that the P3a amplitude, an indicator of attentional resources allocated to a distraction stimulus, was also positively correlated with mindfulness scores (r=0.31, p=0.01), such that lower P3a amplitude was associated with greater mindful attention (mindfulness was negatively coded). Mindfulness is a sought-after characteristic that has many benefits, such as increased ability to selectively focus and increased happiness (Keng, 2011). This study suggests prolonged exposure to nature may be another way to increase mindfulness other than meditation. Additionally, we suggest that exposure to nature may promote mindful attention in a comparable way to meditation.