A 41-year-old man, whose working environment includes many wild birds, visited the emergency department due to aggravated dyspnea and persistent high fever. A chest CT image obtained 2 days after symptom onset (Figure, A) showed ground-glass opacities (GGOs) and consolidation with air bronchograms in the right lower lung lobe and patchy GGOs in the left lower lobe, which progressed (Figure, B) subsequently into consolidations in the bilateral lower lobes and patchy GGOs and consolidations in the middle right lobe and upper left lobe. An initial throat swab screening for influenza A virus was RNA positive, but no specific typing was found 6 days after illness onset. Nearly a month later, the whole gene sequencing (1) of the patient’s samples was positive for avian-origin influenza A (H10N3) virus. After antiviral therapy and sufficient supportive management, the thoracic lesions (Figure, C) were gradually absorbed with mixed residual lesions, and the patient recovered 36 days after illness onset.