The present study aimed to investigate the relationship between lab- and field-based response inhibition tasks and their associations with taekwondo athletes' on-field performance. Twenty-eight senior high-school taekwondo athletes were recruited to participate in this study. Athletes' on-field performances were evaluated by three experts (i.e., national-level coaches) using a 5-point Likert scale based on the observations of regular training and competitive performances. Further, all athletes completed a series of physical fitness and skill tests, as well as response inhibition tasks measured in the lab (i.e., the go/no-go task) and the field (i.e., the go/no-go task designed using BlazePod™ technology). The results revealed that, although a significant correlation was found between lab- and field-based response inhibition measures, only the field-based go/no-go decision-making performance correlated with expert-rated on-field performance. Specifically, this measure was found to be a stronger predictor of on-field performance than anthropometry, physical fitness and taekwondo-specific skill performance. In sum, our findings suggest that using field-based measures for assessing response inhibition offers a greater predictive power for real-life performance, which may be more beneficial for other practical applications.