The purpose of this study was to evaluate the psychometric properties of the Appraisal of Diabetes Scale (ADS) in Korean patients with Type 2 diabetes. The English-language version of the ADS was translated into Korean using a forward-and-backward translation technique. The Korean version of the ADS (ADS-K) was administered to 250 patients who were recruited from two university hospitals. The data were analyzed using principal-component analysis, Cronbach’s alpha, analysis of variance, t test, and Pearson’s correlation. Six of seven items were meaningfully clustered into a two-factor structure by principal-component analysis, these factors accounting for 63.75% of the total variance. The underlying structure was consistent regardless of either gender or the presence of complications. The Cronbach’s alpha of the subscales ranged from .71 to .79, indicating an acceptable internal consistency reliability. As hypothesized, the ADS-K score was moderately correlated with the diabetes-specific quality of life and had satisfactory convergent validity. The known-groups validity of the ADS-K was established using depression groups and HbA1c control status. The ADS-K demonstrated good psychometric properties. In addition, it possessed satisfactory practical properties, such as acceptability and feasibility. Therefore, the ADS-K appears to be suitable for use in both clinical research and clinical practice.