BACKGROUND: Executive dysfunction is commonly impaired in individuals with mild cognitive impairment (MCI). Traditional tools like the Stroop test are widely used to evaluate this domain but lack ecological validity. Virtual reality (VR)-based cognitive assessments, grounded in embodied cognition, may offer a more immersive and sensitive approach to detecting subtle executive dysfunction. METHODS: This study developed and validated a novel VR-based Stroop Test (VRST) that simulates a real-life clothing-sorting task involving incongruent word-color stimuli. A total of 413 older adults (224 healthy controls and 189 with MCI) completed the VRST using a hand-held controller. Behavioral metrics including task completion time, 3D(three-dimensional) trajectory length, and hesitation latency were collected. Participants also underwent traditional assessments: the Korean version of the Montreal Cognitive Assessment (MoCA-K), the paper-based Stroop test, and the Corsi Block Test (CBT). Receiver operating characteristic curves and Spearman correlations were used to analyze discriminant power and construct validity. RESULTS: All VR-derived behavioral markers effectively differentiated older adults with MCI from HCs, with 3D trajectory length showing the highest area under the curve (0.981), followed by hesitation latency (0.967). These surpassed the MoCA-K (0.962). Significant correlations were observed between VRST outcomes and global cognition (MoCA-K), inhibition (Stroop), and working memory (CBT), supporting convergent validity. Importantly, baseline motor abilities did not significantly differ between groups, suggesting that executive function could contributed to performance differences. CONCLUSIONS: The VRST provides a valid, reliable, and scalable means of detecting MCI-related executive dysfunction through embodied cognitive-motor interaction. Its ability to capture subtle behavioral changes in a realistic context suggests strong potential for use in both clinical and community-based cognitive screening settings. TRIAL REGISTRATION: This study was retrospectively registered in the Thai Clinical Trial Registration with identifier TCTR 20250625011.