Background: Carers of children with intellectual disability show high rates of parent-related stress and are at an increased risk for deleterious physical and mental health. Materials and Methods: This study investigated the relationship between demographic and social characteristics and parenting stress, within two different cross-sectional samples of carers: those who care for an adolescent with an intellectual disability and carers from a population based sample. Participants were 1152 carers from the Household Income and Labour Dynamic in Australia study and 284 carers of adolescents with intellectual disabilities from the Ask study. Results and Conclusions: The results supported previous research suggesting carers of children with intellectual disabilities experience high parent-related stress. The results also support the buffer model of social support, as high social support was related to lower parent-related stress. Self-rated prosperity, financial pressure and relationship status were also related to lower levels of parent-related stress.