Granulocyte colony-stimulating factor (G-CSF) is a relatively new drug that is used for recovery of chemotherapy-associated neutropenia. It is known to cause bone pain, headache and fatigue as side-effects; however, large-vessel vasculitis is extremely rare and its relation with G-CSF remains unknown. We describe a 49-year-old woman in whom arteritis developed after chemotherapy and subsequent G-CSF administration. She had experienced pinealoma 3 months ago and received surgery and chemotherapy, leading to neutropenia. After administration of lenograstim at 100 μg/day for 1 week, high fever and neck pain appeared. White blood cell count and serum levels of C-reactive protein and interleukin-6 were increased to 37,930/μL, 23.71 mg/dL, and 241 pg/mL, respectively. Contrast-enhanced computed tomography revealed thickened walls of large vessels including the bilateral common carotid artery (CCA), right brachiocephalic artery, and ascending aorta. Ultrasonography showed wall thickening of the CCA (maximum of intima media thickness: right, 2.9 mm; left, 3.2 mm). As differential diagnoses, infection, chemotherapy, autoimmune diseases, and cancer were considered other than G-CSF. Blood culture tests, lumbar puncture, β-D-glucan tests, and tests for viral antibodies indicated no active infection, and autoantibodies were negative. Empirical antibiotic therapy was ineffective. The score of Naranjo's algorithm to lenograstim was 6, indicating "probable" causality. Considering the clinical course and test results, we made a diagnosis of G-CSF-associated arteritis and commenced glucocorticoid therapy, which drastically improved the symptoms and inflammation. Clinicians should be aware of this uncommon but significant complication of GCS-F administration, for which glucocorticoid treatment can be a useful therapeutic option.