A 52-year-old patient presented with a painless nodular tumor of the upper left eyelid, which was first noticed 6 months prior to the initial presentation. The histopathological and immunohistochemical examination of the excised tumor revealed a mucinous sweat gland carcinoma. This very rare neoplasm (1/150,000 skin lesions) is located within the ocular adnexa in 40 % of cases. If completely excised the prognosis is usually good; however, due to the histological similarity to metastases of an adenocarcinoma, a hitherto unknown primary tumor at another site should be excluded.