Pulmonary eosinophilic granuloma, a rare form of Langerhans cell histiocytosis confined to lung, has no known etiology and variable natural history. It is characterized by discrete proliferation of Langerhans cells. It is known that over 90% of the patients are cigarette smokers, and it is rarely reported in non- or passive-smoking patients, especially female. Here we describe a case of pulmonary eosinophilic granuloma in a passive-smoking, reproductive female patient presented with spontaneous pneumothorax. We identified S-100 and CDla positive histiocytes on immunohistochemical stain of the lung tissue obtained by open lung biopsy.