A 71-year-old woman was admitted to our hospital four times because of high fever and dyspnea from September to November in 2007. We treated her with antibiotics on her first two admissions. HOwever, we suspected hypersensitivity pneumonitis on the third admission because she suffered from fever and dyspnea soon after she had been discharged and returned home. She recovered only with the oxygen therapy on the last two admissions. Computed tomography of the chest showed early phase localized consolidation but changed to ground-glass opacities spreading over the entire lung field later during her third and fourth admissions. Bronchial alveolar lavage showed increases in total cell count, lymphocytes and IgA of pigeon-dropping extracts' and budgerigar-dropping extracts. TBLB showed epithelioid cell granulomas without caseous necrosis and alveolar septal inflammation. Inhalation challenge test using freeze-dried pigeon-dropping extracts was positive, therefore we finally established a diagnosis of acute bird related hypersensitivity pneumonitis. This is apparently the first report of acute bird-related hypersensitivity pneumonitis showing localized consolidation initially and later changing to diffuse ground-glass opacities. These radiological observations are significant in considering the onset and the progression of this disease.