We studied the electron microscopic and immunohistochemical findings in two elderly patients with spindle cell carcinoma of the cornea and conjunctiva. By light microscopy, correct diagnosis was made by finding the transition between the pleomorphic spindle shaped tumor cells and the overlying squamous epithelium. Ultrastructural findings indicated that squamous cell origin included tonofilament-associated desmosomes and keratohyaline granules in the tumor cells. Positive immunohistochemical staining with antikeratin antibodies provided further evidence to prove the origin of spindle cell carcinoma. Follow-up of the two patients showed the malignant tumor to be quite aggressive in terms of intraocular invasion in the first patient and local recurrence in the second.