Sebaceous carcinoma is an aggressive malignancy with a high mortality rate that commonly arises in the periorbital area. Rarely, the lacrimal apparatus may be involved by either contiguous or noncontiguous spread. The authors describe 2 unusual cases of sebaceous carcinoma in the lacrimal sac, presenting as a medial canthal mass simulating chronic dacryocystitis. In Case 1, the sebaceous carcinoma occurred primarily in the lacrimal sac, in the absence of concurrent or previous ocular adnexal sebaceous neoplasia. Mapping biopsies found no evidence of intraepithelial disease. Case 2 developed a late noncontiguous disease recurrence involving the lacrimal sac 5 years postprimary resection of an ipsilateral eyelid sebaceous carcinoma. These cases demonstrate atypical mode of spread of sebaceous carcinoma in lacrimal excretory system. It is important to regard the nasolacrimal drainage system as a potential reservoir for neoplastic sebaceous cells and minimize the risk of tumor cell dissemination during surgical management of eyelid or conjunctival sebaceous cell tumors.