A 78-year-old man was referred to our hospital for assessment of multiple cavitary lesions in the lung. On the day of admission, he had cough, fever, and neutrophilia. Cytologic examination of sputum revealed poorly differentiated carcinoma. Contrast-enhanced computed tomography (CT) showed an enlargement of the left kidney with wall thickening of its pelvis and the left ureter. On a positron emission tomography (PET)/CT scan, fluorodeoxyglucose (FDG) was highly accumulated in this area, in the cavitary lesions in the lung and also in vertebrae, sternum and pelvic bones although the corresponding lesions were not detected on the CT scan. Further cytologic examination of urine and pleural effusion samples also revealed undifferentiated carcinoma cells. The patient died on the 21st day after admission, and posthumous tissue biopsy showed highly dysplastic cell clusters with necrosis in the lung and kidney tissues. Immunohistochemistry further showed granulocyte colony stimulating factor (G-CSF)-positive cells in both tissues, and GATA-3-positive calls in the lung tissues. These findings led to a diagnosis of G-CSF producing urinary tract transitional call carcinoma with pulmonary metastasis and neutrophilia. The accumulation of FDG in several bones on PET/CT may represent a reaction of bone marrow cells to high levels of G-CSF. In the literature, cavitary pulmonary metastasis from a malignant upper urinary tract lesion, as in the present case, is rare.