BACKGROUND: Allergic disorders, including asthma, allergic rhinitis, atopic dermatitis, eosinophilic esophagitis, and food allergy, are a major global health burden. The study and management of allergic disorders is complicated by the considerable heterogeneity in both the presentation and natural history of these disorders. Biorepositories serve as an excellent source of data and biospecimens for delineating subphenotypes of allergic disorders, but such resources are lacking. METHODS: In order to define subphenotypes of allergic disease accurately, we established an infrastructure to link and efficiently utilize clinical and epidemiologic data with biospecimens into a single biorepository called the Greater Cincinnati Pediatric Clinic Repository (GCPCR). Children with allergic disorders as well as healthy controls are followed longitudinally at hospital clinic, emergency department, and inpatient visits. Subjects' asthma, allergy, and skin symptoms; past medical, family, social, diet, and environmental histories; physical activity; medication adherence; perceived quality of life; and demographics are ascertained. DNA is collected from all participants, and other biospecimens such as blood, hair, and nasal epithelial cells are collected on a subset. RESULTS: To date, the GCPCR has 6,317 predominantly Caucasian and African American participants, and 93% have banked DNA. This large sample size supports adequately powered genetic, epidemiologic, environmental, and health disparities studies of childhood allergic diseases. CONCLUSIONS: The GCPCR is a unique biorepository that is continuously evaluated and refined to achieve and maintain rigorous clinical phenotype and biological data. Development of similar disease-specific repositories using common data elements is necessary to enable studies across multiple populations of comprehensively phenotyped patients.