Autoimmunological pulmonary alveolar proteinosis (APAP) is a rare interstitial lung disease with abnormal surfactant homeostasis. Autoimmunological pulmonary alveolar proteinosis is diagnosed most often in the third or fourth decade of life. Predominant symptoms are dyspnea and cough. In most cases, disease is mild but in more severe cases when dyspnea limits patient physical activity a treatment is required. The most common treatment procedure is a whole-lung lavage. We present a case study of 37 years old woman with the patchy consolidations in the chest radiograph. High resolution computed tomography (HRCT) image suggested hipersensivity pneumonitis. At the beginning due to limited disease symptoms no specific proceedings was implemented. After two year follow-up of non-resolving pulmonary changes the decision about open lung biopsy was made. On the basis of histological examination of samples and presence of anty GM-CSF antibodies the diagnosis of autoimmunological pulmonary alveolar proteinosis was established.