Recent research shows veterans with posttraumatic stress disorder (PTSD) are twice as likely as other veterans to develop dementia. However, no studies to date have examined the impact of co-existing PTSD and dementia on family caregivers, who provide the majority of care to these veterans. Using the Stress Process Model, the current investigation explored the similarities and differences in psychosocial, health, and service use outcomes among caregivers assisting veterans with PTSD and dementia compared with caregivers assisting veterans with dementia only. Caregivers of veterans with PTSD and dementia indicated that their relative exhibited more difficult behavior symptoms and used more community services. These caregivers also reported more difficulties understanding veterans’ memory problems and more physical strain. Together, results suggested caregivers of veterans with both PTSD and dementia were at greater risk of negative caregiving consequences. Implications and suggestions for future research are discussed.