Multiple myeloma (MM) is a clonal proliferation of malignant plasma cells mainly affecting the bone marrow. The most common sites of extramedullary dissemination reported in the literature are skin, liver, kidneys, and central nervous system. The presentation of MM with lung plasmacytoma is found to be very uncommon. We report a case of lung plasmacytoma associated with MM. A 65-years-old, non-smoker, female Ethiopian patient presented with 5 months history of dry cough, low grade intermittent fever, fatigue, anemia, hypercalcemia, renal insufficiency and osteolytic lesions in the skull. On a chest X-ray, she had right upper lung opacity with a well-defined margin medially. Fine-needle aspiration cytology from the lung mass lesion confirmed mononucleated and multinucleated plasmacytoid cells. The presentation of MM with lung plasmacytoma is a rare entity. As elderly patients with MM may first present with pneumonia-like presentation, MM or plasmacytoma should be considered as a differential diagnosis in an older patients presenting with thoracic lesion.