A crucial objective of the current study is to determine whether the NVS measurement instrument can be applied in Taiwan. In general, the findings of the current study provide evidence that the concepts embodied in the NVS can be conveyed to Taiwanese people and can be feasibly applied in Taiwan. This study demonstrated that the NVS-TC has high reliability and validity. The association patterns found mostly confirmed a priori hypotheses in direction and strength, thereby supporting the construct validity of the NVS-TC. Differences in the NVS-TC scores among participants with low, intermediate, and high education levels showed evidence of known group validity for the NVS-TC. These differences remained significant in the multivariable regression model after adjustment for age, gender, and diabetes nutrition knowledge. Our results are comparable with international findings regarding the NVS. The mean distribution of the NVS scores varied with participant characteristics. The mean distribution of the NVS-TC (2.11 ± 1.74) was comparable with that of NVS-Netherland (1.8 ± 1.9), as participants had chronic conditions (eg, CAD and T2DM) in both studies, and the mean distribution was much lower than those obtained from general outpatients (eg, NVS-Turkey = 2.6 ± 0.8) or the general population (eg, NVS-UK = 3.47 ± 1.88). Cranach's a of the NVS-TC (a = 0.70) is similar to the coefficients of the NVS-Turkey (a = 0.70) and NVS-Spanish (a = 0.69) and lower than the NVS-Japan (a = 0.72), NVS-UK (a = 0.74), NVS-US (a = 0.76), and NVS-Netherland (a = 0.78). Construct validity was established by comparing the NVS-TC scores with the objective and subjective HL measures. As expected, the NVS-TC had higher correlations with NLS and nutrition knowledge and lower correlations with SQ. The higher correlation between NVS-TC and NLS was because both questionnaires objectively assess numeracy and reading skills. The correlation between NVS-TC and 3BSQ is weaker because 3BSQ is a self-reported measure for a broader range of HL skills, whereas the NVS specifically assesses the ability to identify and interpret text and numerical information. In addition, the low correlation between the objective NVS-TC and subjective 3BSQ is consistent with that obtained by studies in the field of psychometrics; these studies showed the level of correspondence between objective and subjective measures of HL was usually not high. Regarding known group validity, the results confirmed our hypothesis that the NVS-TC could significantly differentiate among patients with high, intermediate, and low education levels. HL research is growing in the field of chronic care because emerging evidence has shown the adverse effects of inadequate HL on health care and outcomes. Developing a validated objective measure of HL skills in individuals with chronic conditions is imperative. This study is one of the few on cross-cultural applicability of HL measures. Cross-cultural adaptation of HL measures is not only essential for further development of HL research in Taiwan but also offers a starting point for feasibility evaluation in patients with diabetes. In addition, the translated NVS can be used in research on cross-cultural differences in HL and associated factors. Although this study illustrates the feasibility of applying the NVS to Taiwan, recognizing its limitations, which are potential research areas, is critical. First, we could not compare the NVS-TC against a standardized HL measure (eg, REALM, TOFHLA, and s-TOFHLA), because no traditional Chinese version of any valid instrument was available when this study was conducted. We therefore used the numeracy skill test, which was validated in a population-based study and had partly overlapping constructs with the NVS. Although this facilitated the establishment of the construct validity of the NVS-TC, further research is required to demonstrate sensitivity and specificity of the NVS-TC for establishing cut-off points of health levels in Taiwan. Second, the research sample in the validation study was recruited from an outpatient department of a hospital. This sample may not be representative of the diabetes population in Taiwan. The effects of HL problems may differ according to context and setting. We therefore recommend that the applicability of the NVS-TC be tested in various studies in public health and health care settings to further investigate its reliability and validity in various contexts and populations. Validating a scale for cross-cultural adaptability is not a task that can be completed in a short period. The test-retest reliability of the NVS-TC is not fully established in the current study; thus, future assessment of reproducibility and responsiveness to health education intervention is necessary. In addition, the NVS-TC has acceptable psychometric properties of reliability and known group validity, but the predictive validity requires further confirmation. Linking the NVS-TC results to actual outcomes such as a decision or history of action would provide a more reliable assessment of the association between the NVS-TC and healthcare behavior.