Objectives. We sought to determine whether unexpected bereavement has a greater impact on mortality in the surviving partner than death of a partner with preexisting chronic disease or disability. Methods. In a UK primary care database (The Health Improvement Network), we identified 171 720 couples aged 60 years and older. We compared the rise in mortality in the first year after bereavement in those whose partner died without recorded chronic disease (unexpected bereavement) to those whose deceased partner had a diagnosis of chronic disease (known morbidity). Results. For unexpected bereavement (13.4% of all bereavements), the adjusted hazard ratio for death in the first year after bereavement was 1.61 (95% confidence interval [CI] = 1.39, 1.86) compared with 1.21 (95% CI = 1.14, 1.30) where the partner had known morbidity. Differences between bereaved groups were significant (P = .001) and present for both men and women. Conclusions. Unexpected bereavement has a greater relative mortality impact than bereavement preceded by chronic disease. Our findings highlight the potential value of preparing individuals for the death of a spouse with known morbidity and providing extra support after bereavement for those experiencing sudden unexpected bereavement.