Multiple myeloma (MM) is a malignant tumor characterized by monoclonal proliferation of plasma cells and is usually seen in older age. In this report, we present a case of atypical localization of a plasmacytoma. Seventy-two years old male patient who had been followed up for 3 years for MM presented to our clinic with low vision for 6 months and a mass in the left eye that showed sudden growth in 1 week. An irregular and vascularized mass was observed in the caruncle region of the left eye. Visual acuity was 7/10 in right eye and hand movements in the left eye. Cataract was present in the left eye and no pathology was detected on ultrasonography. On examination of the right eye, the cornea was clear, the iris was normal, the posterior chamber intraocular lens was present and the fundoscopy was normal. Magnetic resonance imaging revealed an intense contrast enhancement of the mass. A biopsy was performed for pathological examination, and a plasmocytoma was diagnosed. The patient was referred to the hematology clinic for further treatment.