Background: Informal caregivers of individuals with Parkinson's disease face a range of responsibilities that increase as the disease progresses. As a result of these stressors, caregivers are vulnerable to decreased health-related quality of life (HRQOL). Guided by the stress process model of caregiving, the present study examined the relations between family cohesion, perceived burden, and mental and physical HRQOL among Parkinson's disease caregivers in Mexico.