Primary signet ring cell carcinoma of eccrine sweat glands in the eyelid is a very rare tumour with only 8 cases published. We reported a new case in a 74-year-old male. Since the patient refused orbital exenteration a three-dimensional conformal radiation therapy treatment was applied with a total dose of 50,4. Gy, with an excellent local control of the disease. Radiotherapy alone is a good approach for achieving local control in this rare neoplasm