The study and practice of mindfulness is rapidly expanding in Western psychology. Recently developed self-report measures of mindfulness were derived from Western operationalizations and cross-cultural validation of many of these measures is lacking, particularly in Buddhist cultures. Therefore, this study examined the measurement equivalence of the Kentucky Inventory of Mindfulness Skills (KIMS) and Mindful Attention Awareness Scale (MAAS) among Thai (n=385) and American (n=365) college students. Multigroup confirmatory factor analysis models fit to the data revealed that the KIMS lacked configural invariance across groups, which precluded subsequent invariance tests, and although the MAAS demonstrated configural, metric, and partial scalar invariance, there was no significant latent mean MAAS difference between Thais and Americans. These findings suggest that Eastern and Western conceptualizations of mindfulness may have important differences.