Our aim in this study was to validate a stress-process model for Hispanic caregivers of adults with mental retardation that incorporates family functioning. The model postulates that maladaptive adult behaviors are related to poorer family relationships and higher levels of family burden, which in turn is related to caregiver psychological distress and self-reported health. The 153 Hispanic caregivers were interviewed in their homes with structured interviews and self-report measures. We analyzed cross-sectional data using structural equation modeling. The hypothesized model provided an excellent fit to the data. Also, family relationships mediated the relationship between maladaptive adult behaviors and family burden, and higher levels of family burden were related to greater caregiver distress. Acculturation was negatively related to caregiver distress.