Ankylosing spondylitis (AS) is a chronic inflammatory disorder, commonly characterized by inflammation of axial skeleton and development of enthesopathies. Tumor necrosis factor inhibitors (TNFi) shows good therapeutic responses in AS patients without good response to non-steroidal anti-inflammatory drugs. Although TNFi are relatively safe for AS patients, serious opportunistic infections, including tuberculosis and fungal infection, could develop. Here, according to our knowledge, we report a first Korean case of pulmonary cryptococcosis in a patient with AS treated with etanercept. A 64 year-old man with AS visited due to a newly appeared pulmonary nodule on a routine chest radiography. He had been administered etanercept for 5 months. Histologic findings of the lung nodule showed characteristic features of cryptococcosis. Etanercept was discontinued and oral fluconazole was administrated, as there was no evidence of central nervous system involvement. After 7 months of treatment, chest CT showed an improvement of the pulmonary lesion.