Introduction: To date, no study has explored associations between objective stress-related biomarkers (i.e., inflammatory markers, diurnal rhythm of cortisol) and health-related quality of life (HRQOL) in Latina breast cancer survivors and their informal caregivers (i.e., family, friends). Method: This cross-sectional feasibility study assessed saliva C-reactive protein, saliva diurnal cortisol rhythm (cortisol slope), and self-reported HRQOL (psychological, physical, and social domains) in 22 Latina survivor–caregiver dyads.