Background: Caregivers of a family member with a chronic disability or illness such as dementia are at increased risk for chronic disease. There are many factors that contribute to dementia caregiver vulnerability and these factors can be challenging to assess in clinical settings. Self-rated health (SRH) is an independent measure of survival and physical health in the elderly. As an inclusive measure of health, SRH has been proposed as a reliable way to assess a patient's general health in primary care. Therefore, we sought to identify determinants of poor/fair SRH versus categories of at least good SRH in informal caregivers.; Methods: In a cross-sectional study, we examined 134 elderly (≥55 years) providing in-home care for a spouse with dementia who rated their own health with a single-item question: "In general, would you say your health is excellent, very good, good, fair or poor?". In a multivariable model, we compared caregivers with poor/fair SRH to those with good, very good, or excellent SRH on demographics, health characteristics (health behaviors, physical health indicators, psychosocial factors) and caregiving-specific stress (a composite index/total of four caregiving-specific stressors: years of caregiving, dementia severity, care recipient functional impairment and perceived caregiver burden).; Results: Compared with caregivers who rated their own health as either good (31.3%), very good (38.8%) or excellent (14.2%), caregivers with poor/fair SRH (15.7%) were more likely to have lower physical function and total greater caregiving-specific stress. More years of caregiving, severe dementia and care recipient functional impairment, but not perceived caregiver burden, were also more likely among caregivers with poor/fair SRH. Additionally, high negative affect and low positive affect were more likely in caregivers with poor/fair vs. good or excellent and very good or excellent SRH, respectively.; Conclusions: Caregivers with poor/fair SRH were characterized by higher levels of medical comorbidity, low physical function, high negative, but low positive affect and longer duration of caregiving, as well as more severe dementia and greater functional impairment of the care recipient. These findings suggest that caregivers need to be more closely evaluated and targeted for preventive interventions in clinical practice.; Trial Registration: ClinicalTrials.gov registration number: NCT02317523 .