Despite the increased use of measures developed in the United States in countries with different cultural value orientations, researchers often do not examine whether scales show invariance across cultures. The goal of this study was to discuss the importance of measurement invariance when conducting research with cultural groups that differ from U.S. populations. As an illustration of this issue, the Marital Comparison Level Index (MCLI; Sabatelli, 1984 ) was revised in a culturally relevant way to be used to study Korean couples and the measurement properties of the scale was explored in samples drawn from the United States and Korea ( N = 676). Results showed that there was a second-order factor, which is marital complaints, that underlies the five first-order factors (i.e., emotional intimacy, sexual intimacy, marital conflicts, intergenerational relationships, and complaints about partner’s lifestyle). The identified second-order factor structure showed an adequate level of measurement invariance, indicating the potential for using the measure to examine marital issues within and between couples from these two countries. Taken together, the present study serves as an impetus for international scholarship that could promote cultural and racial diversity in relationship research.