Little is known about mental health service use among children with anxiety disorders, and even less is known about these children in public sectors of care. In this study, 1,715 children were randomly sampled from one of five public service systems. Psychiatric diagnoses were assessed with a structured interview, and standardized measures were used to assess mental health service utilization. Data from a subsample (n = 779) of youth with psychiatric disorders were analyzed. Analyses revealed that comorbidity among children with anxiety disorders was substantially higher than general population estimates. Approximately 26% of children with anxiety had a comorbid mood disorder, and 62% had a disruptive behavior disorder. Among children with anxiety disorders, those who had comorbid conditions were more likely to receive inpatient services than those without comorbidity. Comorbidity, caregiver strain, and service sector were associated with inpatient and nonspecialty service use in this group. Findings underscore the substantial comorbidity among children with anxiety disorders in public sectors of care and the potential need to adapt evidence-based interventions to meet the complex and multiple needs of these children.