Informal home care is prevalent among Mexican American stroke survivors, but data on the impact on caregivers are not available. The aim was to assess ethnic differences in informal stroke caregiving and caregiver outcomes at 90 days poststroke. Informal caregivers were recruited from the population-based Brain Attack Surveillance in Corpus Christi Project (2019-2023), conducted in a bi-ethnic community in Texas. Caregivers of community-dwelling stroke survivors who were not cognitively impaired and not employed by a formal caregiving agency were interviewed. Interviews included sociodemographics, dyad characteristics, Modified Caregiver Strain Index (range 0-26, higher more positive), Positive Aspects of Caregiving scale (range, 5-45, higher more), Patient Health Questionnaire-8 (range, 0-30, higher worse), and PROMIS (Patient-Reported Outcomes Measurement Information System)-10 physical (range, 16.2-67.7, higher better) and mental health (range, 21.2-67.6, higher better) summary scores. Stroke survivor data was from interviews and medical records. Propensity score methods were used to balance caregiver and patient factors among Mexican American and Non-Hispanic White caregivers by fitting a model with ethnicity of caregiver as the outcome and predictors being caregiver sociodemographics, patient-caregiver dyad characteristics, and patient sociodemographics and functional disability. Propensity scores were included as a covariate in regression models, considering the association between ethnicity and outcomes. Mexican American caregivers were younger, more likely female, and more likely a child of the stroke survivor than Non-Hispanic White caregivers. Mexican American caregiver ethnicity was associated with less caregiver strain (β, -1.87 [95% CI, -3.51 to -0.22]) and depressive symptoms (β, -2.02 [95% CI, -3.41 to -0.64]) and more favorable mental health (β, 4.90 [95% CI, 2.49-7.31]) and positive aspects of caregiving (β, 3.29 [95% CI, 1.35-5.23]) but not associated with physical health. Understanding the mechanisms behind more favorable caregiver outcomes in Mexican American people may aid in the design of culturally sensitive interventions to improve both caregiver and stroke survivor outcomes, potentially across all race and ethnic groups.