Background: Taiwanese family carers of people with intellectual disabilities not only suffer from long-term stress but also need to cope with social difficulties. The aim of this study is to evaluate the quality of life (QOL) among family carers of people with intellectual disabilities. Materials and methods: A census interview survey was conducted in Hsin-Chu City in Taiwan and included the primary family caregivers of 792 adults with intellectual disability who were living with their families. The survey packet contained the WHOQOL-BREF Taiwan-version scale with four core domains and the activities of daily life/instrumental activities of daily life (ADL/IADL) scales. Results: The mean score for "physical" was highest and that for "environment" was lowest. The strongest predictors of caregivers QOL were the caregiver's health status, their family income and the level of severity of the intellectual disability of the adult. Conclusions: The results of the study support the need to expand services and individualize support to families of adults with intellectual disability living in family homes.