Hyper-IgE syndrome (HIES), or Jobs disease, is a rare immunologic disorder characterized by the triad of staphylococcal abscesses, pneumonia with pneumatocele formation, and elevated IgE. It has been shown to have multiple modes of inheritance, autosomal dominant being more common than autosomal recessive, with sporadic cases as well. A mutation in signal transducer and activator of transcription 3 (STAT3) gene has been linked to the development of the sporadic and dominant forms of HIES. Peripheral eosinophilia, typically greater than two standard deviations from the normal population, is often seen in association with HIES. Despite these elevated levels of blood eosinophils, there have been no reported cases of invasive eosinophilic disease, such as eosonophilic esophagitic. Here we report the first description, to our knowledge, of a patient with HIES with a STAT3 mutation involving exon 12, Thr389Ile, and invasive eosinophilic disease of the esophagus. STAT3 modulates the expression of several genes that control central cell processes such as growth and death in response to external soluble stimuli. A mutation in the STAT3 molecule may affect the eosinophil's response to IL-5 and thus reduce the chemotaxic ability of those cells to migrate into tissues. This may then explain the paucity of eosinophilic infiltrative disease in patients with STAT3 mutations. The level of eosinophilic involvement may be related to the site or type of mutation within the STAT3 molecule. As more data are collected, we may be able to assess whether certain mutations dictate different clinical outcomes, which could prove helpful in directing therapy.