A 78-year-old man suffered an unusual variant of sweat gland carcinoma of the eyelid. This disorder is seldom recognized, and is frequently confused with inflammation, benign neoplasms, and metastatic carcinomas. On the basis of clinicopathologic and ultrastructural features found by both light and electron microscopy, we diagnosed sweat gland carcinoma of the eyelid. We considered the possibility of metastasis from a primary carcinoma elsewhere in the patient.