The objective of this study was to assess the factorial invariance and convergent validity of the Group-Based Medical Mistrust Scale (GBMMS) across gender (male and female) and ethnoracial identity (Latino and Black). Minority students (N = 686) attending a southeastern university were surveyed in the fall of 2011. Psychometric analysis of the GBMMS was performed. A three-factor solution fit the data after the omission of two problematic items. This revised version of the GBMMS exhibited sufficient configural, metric, and scalar invariance. Convergence of the GBMMS with conceptually related measures provided further evidence of validity; however, there was variation across ethnoracial identity. The GBMMS has viable psychometric properties across gender and ethnoracial identity in Black and Latino populations.