Background: Dementia caregiving has been associated with a range of adverse effects on the physical health of the caregiver. However, the specific mechanisms underlying the relationship between dementia caregiver stress and ill health remain unclear. Objectives: The aim of this study was to investigate, using available prospective data, the relationship between perceived stress (burden) and pre-clinical indices of ill-health (cortisol awakening response and secretory immunoglobulin A) amongst dementia caregivers.