Extramedullary plasmacytoma(EMP) is a rare tumor that originates as a clone of malignant transformed plasma cells. EMPs make up 4% of all plasma cell tumors and 90% of EMP cases occur in the head and neck area. The diagnosis of EMP is based on the morphologic and immunophenotypical finding of a localized collection of monoclonal plasma cells in the absence of plasma cell proliferation elsewhere. Patients with EMP can be treated by surgery or radiotherapy alone or in combination. EMP has good prognosis but long-term follow-up is critical because local recurrence or systemic progression to multiple myeloma may develop more than 30 years after the initial diagnosis of EMP. We report a case of EMP in palatine tonsil of 21-year old man who was treated successfully by radiotherapy alone.