Plasmacytomas are a localized proliferation of plasma cells in the bone marrow and are less frequently seen in extraosseous organs or tissues. Extraosseous plasmacytoma is a rare malignant neoplasm and constitutes 3–5% of all plasma cell neoplasms. In this article, we describe a case of a patient with extraosseous plasmacytoma of the maxilla and the related computed tomography (CT) and magnetic resonance imaging (MRI) findings.