The present study was conducted to develop and validate a psychological scale that measures individuals’ attitude toward unification of Korea (ATU-K). Building on major theoretical perspectives on the structure of attitude and the attitude-behavior link, we specified two sub-components each representing the cognitive and the affective dimension of people’s attitude toward unification. In a survey that involved a stratified sample of Korean adults (N = 1,500), we found strong evidence showing the construct validity of ATU-K. We also found evidence for the convergent and discriminant validity of the scale. In a second survey involving a stratified sample of 1,500 Korean adults, we found the utility of ATU-K in predicting people’s intention to engage in unification-oriented behavior. We also found that ATU-K fares better in predicting the intention vis-a-vis the other measures of unification-related beliefs reported in previous research. We discuss implications of our findings and directions for future research.