Although primary ocular lymphomas may be found in the conjunctiva, eye lids and lacrimal glands, the majority nevertheless occur in the orbit. Only a few cases of primary conjunctival lymphoma have been described in the literature. A 68-year-old man presented with a painless swelling of the epibulbar conjunctiva of the right eye. A diffuse lymphoid infiltrate consisting of small-sized lymphoid cells with the morphology and distribution characteristics of mucosa-associated lymphoid tissue was observed. Immunohistological study demonstrated the B lymphocyte lineage of tumor cells and Bcl-1 and bcl-2 rearrangements were negative. After clinical staging including thoracic, abdominal, brain and orbital CT scans, fiberoptic gastroscopy and bone marrow biopsy, no other foci of this lymphoma were found. Radiation therapy was given and the patient currently remains free of lymphoma 30 months after diagnosis.