Researchers are increasingly studying close relationships across cultural contexts. One issue that arises when applying scales originally developed in Western countries to a different cultural context is measurement invariance. Researchers often do not examine whether scales show invariance across cultures and thus can be used with confidence. The goal of this article is to discuss the importance of measurement invariance, to discuss what testing invariance involves, and to test the measurement properties of scales of relationship satisfaction, commitment, intimacy, and trust across 4 samples (United States, Canada, Indonesia, and China). Analyses indicated that weak measurement invariance was met for all 4 scales, and assumptions of strong measurement invariance had to be relaxed for only a few items in each scale. Findings are discussed and recommendations are made regarding using these or other scales that have been shown to meet assumptions of invariance across different cultural groups.