We investigated autonomic and endocrine responses to acute stressors in 27 women who were or are presently caring for a spouse with a progressive dementia (high chronic stress) and 37 noncaregivers who were category matched for age and family income (low chronic stress). Measures were taken before (low acute stress) and in response to brief laboratory stressors (high acute stress). We replicated prior research showing that caregivers report greater stress, depression, and loneliness than the comparison groups, and acute stressors elevate autonomic and neuroendocrine activity. We also found that caregivers, relative to noncaregivers, exhibited shorter preejection periods and elevated blood pressure and heart rate, but the magnitude of autonomic and neuroendocrine reactivity to the experimental stressors was comparable across these groups. This pattern of autonomic differentiation replicates prior research showing that caregivers are characterized by higher sympathetic activation than noncaregivers and suggests that the effects of chronic stress on physiological reactivity may be a less robust effect in older adults.