Eosinophilic granulomatosis with polyangiitis (EGPA) refers to systemic vasculitis in patients with bronchial asthma and eosinophilic rhinosinusitis. Dupilumab has been approved for the treatment of asthma, eosinophilic rhinosinusitis, and atopic dermatitis. A man in his 50s with a history of asthma and eosinophilic rhinosinusitis with nasal polyposis developed high fever and dyspnea while undergoing dupilumab treatment. Laboratory examinations identified hypereosinophilia. Chest radiography and computed tomography revealed right-sided tracheal dislocation, extensive consolidation, and ground-glass opacities with traction bronchiectasis. Evidence of interstitial pneumonia, eosinophilia, and increased eosinophil counts in the bronchoalveolar lavage fluid was observed. We diagnosed the patient with EGPA and administered corticosteroids, which improved his symptoms and radiographic signs. Although the relationship between EGPA and dupilumab treatment is unclear, EGPA may have been exacerbated by dupilumab in this case. Therefore, when administering dupilumab to patients with partial symptoms of EGPA, care should be taken to monitor for adverse symptom development and exacerbation.