BACKGROUND: Caring for a chronically ill spouse is stressful, but the health effects of caregiving are not fully understood. We studied the effect on mortality of being married to a person with Parkinson disease. METHODS: All patients in Denmark with a first-time hospitalization for Parkinson disease between 1986 and 2009 were identified, and each case was matched to five population controls. We further identified all spouses of those with Parkinson disease (n = 8,515) and also the spouses of controls (n = 43,432). All spouses were followed in nationwide registries until 2011. RESULTS: Among men, being married to a Parkinson disease patient was associated with a slightly higher risk of all-cause mortality (hazard ratio = 1.06 [95% confidence interval = 1.00-1.11]). Mortality was particularly high for death due to external causes (1.42 [1.09-1.84]) including suicide (1.89 [1.05-3.42]) and death from undefined symptoms/abnormal findings (1.25 [1.07-1.47]). Censoring at the time of death of the patient attenuated the findings for all-cause mortality in husbands (1.02 [0.95-1.09]), indicating that part of the association is with bereavement. Still, living with a person with Parkinson disease 5 years after first Parkinson hospitalization was associated with higher risk of all-cause mortality for both husbands (1.15 [1.07-1.23]) and wives (1.11 [1.04-1.17]). CONCLUSIONS: Caring for a spouse with a serious chronic illness is associated with a slight but consistent elevation in mortality risk.