Granulocyte colony-stimulating factor (G-CSF) promotes neutrophil production. G-CSF-producing tumors have a feature of neutrophilia without infection, and most patients with G-CSF-producing tumors show an aggressive clinical course and poor prognosis. A 71-year-old woman was diagnosed with left lung cancer, cT4N1M0, stage IIIA. Severe neutrophilia and bone marrow uptake in 18-fluorodeoxyglucose-positron emission tomography suggested the possibility of G-CSF-producing lung cancer. Following neoadjuvant radiation chemotherapy, left lower lobectomy and left upper lobe partial resection were performed. According to pathology findings of the resected specimen, the patient was diagnosed with G-CSF-producing left lung squamous cell carcinoma. Moreover, genetic tests showed that the tumor cells were positive for c-ros oncogene 1 (ROS1) rearrangements. To our knowledge, this is the first reported case of G-CSF-producing lung cancer with ROS1 rearrangements, and complete resection was performed successfully after neoadjuvant radiation chemotherapy.