BACKGROUND:Concerns have been raised about access to cancer screening and the timely receipt of cancer care for people with an intellectual disability (ID). However, knowledge about cancer mortality as a potential consequence of these disparities is still limited. This study, therefore, compared cancer-related mortality patterns between people with and without ID. METHODS: A historical cohort study (2015-2019) linked the Dutch adult population (approximately 12 million people with an ID prevalence of 1.45%) and mortality registries. Cancer-related mortality was identified by the underlying cause of death (according to the chapter on neoplasms in the International Classification of Diseases, Tenth Revision). Observed mortality and calculated age-and sex-standardized mortality ratios (SMRs) with 95% confidence intervals (CIs) were reported. RESULTS: There were 11,102 deaths in the ID population (21.7% cancer-related; n = 2408) and 730,405 deaths in the general population (31.2%; n = 228,120) available for analysis. Cancer was noted as the cause of death more often among people with ID in comparison with the general population (SMR, 1.48; 95% CI, 1.42-1.54), particularly in the young age groups. High-mortality cancers included cancers within the national screening program (SMRs,, digestive cancers (SMRs, 1.24-2.56), bladder cancer (SMR, 2.07; 95% CI, 1.61-2.54), and cancers of unknown primary (SMR, 2.48; 95% CI, 2.06-2.89). CONCLUSIONS: Cancer was reported as the cause of death approximately 1.5 times more often in people with ID compared with the general population. This mortality disparity may indicate adverse effects from inequalities in screening and cancer care experienced by people with ID.