A 68-year-old man was found to have tumors of the left lung and left conjunctiva. Thoracoscopic partial lung resection was performed. Histological examination revealed diffuse proliferations of centrocyte-like cells with lymphoepithelial lesions, and a diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma was made. Immunohistochemical study and flow cytometric analysis were also compatible with MALT lymphoma. Conjunctival tumor biopsy was performed and the diagnosis was confirmed. The postoperative course of the patient was uneventful, and he is currently being followed without further treatment.