This study aims to validate the revised Compound Psychological Capital scale (CPC-12R) which is a recently published inventory for measuring psychological capital across contexts. The data from three representative samples of employees from the U.S. (n = 456), the Czech Republic (n = 966), and Slovakia (n = 965) revealed a weak measurement invariance across the three cultures, a high internal consistency of all subscales and a good fit of the data to the theoretical model of psychological capital. The data obtained by means of the English version of the CPC-12R showed a very strong correlation with the established Psychological Capital Questionnaire (PCQ), medium to strong positive correlations with work engagement, job satisfaction and positive affect, and a weak negative correlation with negative affect. Therefore, this study demonstrates the reliability and factorial, concurrent and convergent validity of CPC-12R in the context of organizations. The study also provides indicative norms for measuring psychological capital in three populations and refers to the limitations of the CPC-12R, in particular, the very small residual variance in first-order factors and the lack of strong invariance across cultures, which prevents a meaningful comparison of factor means across countries.