Purpose: Tumors producing granulocyte colony stimulating factor (G-CSF) are quite rare, and features of clinical examinations are not well known. Particularly in G-CSF producing esophageal tumors, only a few reports are available concerning EUS and FDG-PET features. Methods: We present a case of G-CSF producing esophageal squamous cell carcinoma showing interesting features of EUS and FDG-PET imaging findings, and changes of clinical examinations with a treatment course were analyzed. Results: A 58-year-old Japanese man had type I esophageal cancer with marked lymph node metastases associated with leukocytosis and elevated serum G-CSF, IL-6, CRP, and SCC. Repeated biopsy showed poorly differentiated squamous cell carcinoma, not carcinosarcoma. Although the primary lesion was negative for G-CSF by immunohistochemistry, a highly increased G-CSF m-RNA level, measured using reverse transcriptase-polymerase chain reaction in frozen sections, led to a diagnosis of GCSF-producing esohageal cancer. Before treatment, esophagoscopy showed 5 cm tumor with a steep slope in the middle thoracic esophagus, and EUS showed a low echoic mass with the mixture of a high echoic area in the 1st∼3rd layer. Contrary to the tumor size, the depth of tumor invasion was relatively shallow, T1 (SM with massive invasionor), or T2 (MP with slight invasion). FDG-PET scanning showed a significantly high uptake in the main tumor, abdominal lymph nodes and the bones. Uptake in the bone was symmetrically found in the red pulp throughout the body. This patient was diagnosed as stage 4 esophageal squamous cell carcinoma and received 1st line chemotherapy with 5-FU and cisplatin. This regimen led to progressive disease and worse performance status. He selected another chemotherapy, not best supportive care, and 2nd line treatment with irrinotecan monotherapy enabled partial response during five months. He died 10 months after the 2nd line chemotherapy with irrinotecan due to the progression of tumors. Throughout the treatment course, FDG uptake in the bone changed along with the change of the leukocytes, serum G-CSF, IL-6, CRP and SCC. Conclusion: When detecting esophageal tumor with a steep slope, serum G-CSF, IL-6, and CRP must be checked in consideration of G-CSF producing cancer. EUS and FDG-PET attribute to the diagnosis. Irrinotecan monotherapy can be one of the effective regimens for non-operable G-CSF producing esophageal cancer.