Sebaceous gland carcinoma usually arises from meibomian or Zeis glands deep within the eyelid, but it can rarely arise within the conjunctival epithelium without a deep component. We describe a woman with a history of chronic blepharoconjunctivitis unresponsive to topical medications. Examination disclosed confluent papillary hypertrophy of the upper palpebral conjunctiva and deposits of white flaky material. Tarsoconjunctival punch biopsy revealed intraepithelial sebaceous gland carcinoma. Management consisted of frozen section-controlled complete tumor excision with removal of the entire posterior lamella of the right upper eyelid, cryotherapy to the margins, and reconstruction. Histopathologic analysis confirmed primary sebaceous gland carcinoma localized to the conjunctival epithelium without involvement of underlying meibomian or Zeis glands or the caruncle. Patients with unexplained chronic unilateral blepharoconjunctivitis or papillary hypertrophy of the palpebral conjunctiva should be considered for biopsy to rule out neoplasia, even when there is no sign of an underlying eyelid mass.