Primary pulmonary lymphoepithelioma-like carcinoma (LELC) is rare, with a more favorable prognosis compared with that of other types of non-small cell lung cancers. Herein, we describe an interesting case of primary pulmonary LELC confirmed postoperatively, which had been initially diagnosed as poorly differentiated adenocarcinoma. We suggest that despite the rarity of pulmonary LELC, it should be included as one of the differential diagnoses for lung malignancies. Physicians should consider taking a larger biopsy, especially when histologic examination shows undifferentiated nature.