In some cases, parents caring for an adult child with an intellectual and/or developmental disability (IDD) must balance this with caregiving for another family member. This dual responsibility, referred to as "compound caregiving", may contribute to increased feelings of distress, or change their perceived ability to care for their child. The current study examined how compound caregivers differ from other parents of adults with IDD, and whether compound caregiving is significantly associated with family distress. Data was available for 199 parents aged 38 to 91 years who were seeking adult services for their son or daughter with IDD. Parents completed a mailed questionnaire and telephone interview in which they indicated compound caregiver responsibilities. Parents identified as compound caregivers were then compared to those who were not in terms of family characteristics, as well as parental perceptions of burden and mastery, and family distress as measured by the Revised Caregiver Appraisal Scale and the Brief Family Distress Scale, respectively. Nearly half of the parents reported being compound caregivers. The demographic profile of these parents was no different from that of the other parents but their children were slightly younger. Compound caregiving was significantly associated with parental perceptions of burden and mastery and family distress. Demands outside of caring for an adult child with IDD can negatively influence family functioning and must be included as part of caregiving assessments.