Gender roles are a basic organizing feature in Latina/o families (Cauce & Domenech-Rodriguez, 2002), in which female and male gender roles are clearly defined and are captured by the constructs of marianismo (Castillo, Perez, Castillo, & Ghosheh, 2010) and machismo (Arciniega, Anderson, Tovar-Blank, & Tracey, 2008), respectively. Latina/o adolescents are socialized to Latina/o culture's gender role beliefs and expectations; however, research tends to be limited to its respective gender (e.g., studies of marianismo focusing only on women). The present study seeks to validate and explore gender differences in the Marianismo Beliefs Scale (MBS; Castillo et al., 2010) with both Mexican American adolescent boys and girls. Participants were 524 Mexican American adolescents in a midsized South Texas city. A categorical confirmatory factor analysis (CCFA) was performed to test the factor structure and measurement invariance across gender. Results of the CCFA provided a modified 5-factor version of the MBS-the Marianismo Beliefs Scale-Adolescent Version (MBSA). Cross-group mean comparisons indicate that girls endorsed higher levels of family pillar and spiritual pillar beliefs, whereas the boys scored significantly higher on beliefs that Latinas should self-silence to maintain harmony and should be subordinate to others. No gender differences were present for beliefs on Latinas being virtuous and chaste. The MBSA will be discussed in reference to its developmental and gender appropriateness in future research and clinical practice.