Periostin is a 90-kDa member of the fasciclin-containing family; it functions as part of matricellular proteins, and its production by airway epithelial cells is induced by IL-4 and IL-13. Periostin is secreted by fibroblasts and upregulated in the airway epithelia of patients with bronchial asthma; it is considered to contribute to remodeling under this pathological condition. However, despite many studies in diverse research areas, our overall understanding of this intriguing molecule is still inadequate. Here, we integrate the available evidence on periostin expression and its roles in otolaryngological diseases, including allergic rhinitis, chronic rhinosinusitis with nasal polyps, aspirin-induced asthma, organized hematoma, eosinophilic otitis media, and IgG4-related disease. Periostin might be involved as an important structural mediator in pathological processes such as insult and injury, Th2-driven inflammation, extracellular matrix restructuring, fibrosclerosis, tumor angiogenesis, and tissue remodeling.