The National Intellectual Disability Database that operates in the Republic of Ireland is unique in Europe and provides an opportunity to examine trends over time for a total population in excess of 25,000 people with intellectual disabilities and their care arrangements. This paper describes the changes over a 10-year period in the proportion of children and adults living with lone parent carers and comparisons are drawn with demographic changes as reflected in the national census of 2001 and 2006. Since 1996, the proportion of children and young people under 20 years of age with intellectual disabilities living with lone parents has doubled: in 2006 nearly one-in-five were in lone parent households. These figures are lower than for the general population although they reflect similar demographic trends. The increase in lone parenting is more marked amongst people who have mild rather than moderate to profound intellectual disabilities and for those families living outside the Greater Dublin area. The implications for providing equitable and supportive family-centred services to this population of parent carers are discussed.