This study examined child anxiety as a potential moderator of the relationship between parenting stress and child physical health. Low-income youth (N = 109, M = 9.51 years old) and their parents completed measures of anxiety, health-related quality of life, and parenting stress in an outpatient clinic. As an objective measure of physical health, medical service utilization was extracted from medical records. Parenting stress was associated significantly with worse health-related quality of life and higher service utilization. Child anxiety moderated the relationship between stress and health. Health psychologists should target both family stress and child anxiety in promoting better health outcomes among low-income families.