Background: At present, there is limited statistical information about mortality of people with intellectual disabilities in England. This study explores the data that are currently available. Materials and Methods: Four recent sources of data about mortality of people with intellectual disabilities in England are reviewed: the Confidential Inquiry into Premature Deaths of People with intellectual disabilities (CIPOLD); the 2013 Joint Health and Social Care Intellectual Disability Self-assessment Exercise; local registers of people with intellectual disability; and analysis of Cause of Death certificates. Results: Available data confirm that people with intellectual disability have a shorter lifespan and increased risk of early death when compared with the general population. The standardized mortality rate for people with intellectual disabilities is approximately twice that of the general population in England, with little indication of any reduction in this over time. Conclusions: Comprehensive data about mortality of people with intellectual disabilities that take account of the age and sex distribution of the population are currently lacking in England. Existing data suggest persistent inequalities between people with intellectual disabilities and the general population. There is an urgent need for better monitoring mechanisms and actions to address these.