Hypersensitivity pneumonitis (HP), is an inflammatory disease that represents one possible response of the interstitial and parenchymal tissue to the intensive and repeated inhalation of organic dusts or reactive chemicals substances. In this case report, for the first time in the literature as we know, acute hypersensitivity pneumonitis in a patient who working in broom grass manufacturing were presented. Broom manufacturer employee 35 years old female patient was admitted with dyspnea, fever and cough, beginning the three months before. Physical examination, there were bilateral basal crackles. On Thorax CT bilateral diffuse ground-glass opacity and mosaic perfusion were observed. Patient was hospitalized, IV prednisolone therapy was started. Almost complete clinical improvement was achieved. We would like to emphasize that detailed occupational history should be questioned; because; diagnosis of acute HP, due to the mixing with the viral infection or atypical pneumonia, easily skipped.