Mild cognitive impairment (MCI) has been recognized as a window of opportunity for therapeutic and preventive measures to slow cognitive decline. The current study investigated the efficacy of the virtual reality (VR) cognitive-based intervention on verbal and visuospatial short-term memory (STM), executive functions (EFs), and wellbeing among older adults with and without MCI. The immersive VR cognitive-based intervention comprised eight 60-minute sessions, held twice a week over a span of 30 days. The participants consisted of 31 non-MCI older adults in the experimental group (mean age ± = 66.31 ± 3.12 years), 29 older adults with MCI in the experimental group (mean age ± = 68.19 ± 5.03 years), and 30 non-MCI older adults in the control group (mean age ± = 64.97 ± 3.35 years). The dependent variables were assessed by using a battery of computerized test, the well-being of older people questionnaire and resting-state EEG. A repeated-measures ANCOVA was employed to examine the effects of the developed VR intervention. Significant improvements were observed in both STMs and EFs following the intervention, as indicated by behavioral and EEG findings, ranging from small to large effect sizes (i.e., = .05-.17). However, enhanced wellbeing was specifically observed among older adults with MCI in the experimental group, (2, 87) = 6.78, .01, = .11. The present findings lend support to the efficacy of VR cognitive-based interventions across clinical and non-clinical populations. These results underscore the immediate impact of the intervention across multimodal assessments, including neurophysiological changes, cognitive, and behavioral outcomes.