A 16-year-old boy with asthma participated in recovery volunteer work following the 2018 heavy rains in Japan. One month later, he experienced chest pain and dyspnea. Chest computed tomography revealed a cavity with a fungal ball, and Aspergillus fumigatus was detected in his bronchoalveolar lavage fluid. He was treated with voriconazole, but new consolidations appeared rapidly. He also experienced allergic bronchopulmonary aspergillosis. After prednisolone prescription, the consolidations improved; however, his asthma worsened. He underwent partial lung resection to avoid allergens, and his symptoms improved. We must recognize cases of infection after a disaster, especially in patients with chronic respiratory diseases.