Acculturative stress is commonly experienced among Latinx immigrants in the United States who may feel pressured to maintain their heritage cultural norms and beliefs and/or adopt norms and beliefs of the dominant culture. The present study examined longitudinal relations between acculturative stress and endorsement of traditional Latina gender role beliefs (i.e., marianismo). We determined strength of the relations and temporal precedence of acculturative stress and endorsement of marianismo across 3 time points during participants' initial 3 years in the United States using a random intercept cross-lagged panel model. Participants were 530 Latina young adult women (ages 18-23) recruited from Miami-Dade County, Florida. Results suggested that acculturative stress levels at Time 1 positively predicted endorsement of the Family Pillar belief at Time 2, but acculturative stress levels at Time 2 negatively predicted the Virtuous and Chaste and Subordinate to Others beliefs at Time 3. In terms of marianismo beliefs predicting acculturative stress levels over time, the Virtuous and Chaste belief at Time 1 positively predicted acculturative stress at Time 2, and the Silencing Self to Maintain Harmony belief at Time 2 positively predicted acculturative stress at Time 3. Findings suggest that the Family Pillar belief, or feeling responsibility for the family's unity, may be protective against acculturative stress over time. Endorsing certain gender role beliefs (i.e., Virtuous and Chaste, Subordinate to Others) may lead to greater acculturative stress, and Latina young adult women experiencing acculturative stress may alter their endorsement of marianismo beliefs in an attempt to resolve culturally conflicting stress experienced after immigration. (PsycINFO Database Record (c) 2019 APA, all rights reserved).