Mucosa-associated lymphoid tissue(MALT) lymphoma is thought to originate from marginal zone B-cells. In the WHO classification, Extranodal marginal zone lymphoma of MALT is classified B-cell Non-Hodgkin lymphoma. Common sites of MALT lymphoma include stomach, lung and the ocular-adnexa. Although less common in other sites, it is the most common low-grade lymphoma of the breast, thyroid, bowel skin and soft tissue. No strong age or gender predominance exists in MALT lymphoma. Dissemination to other sites can occur. In the oral cavity, MALT lymphoma is rare. Herein, we present a case of intra-oral MALT lymphoma. 66 year-old woman without any background of immunodeficiency or autoimmune disease admitted department of oral & maxillofacial surgery in Ulsan university hospital for evaluation of long-standing mild upper lip swelling. The lesion was completely resected and biopsied. Histological and immunohistochemical stains(CD3, CD5, CD20, CD21, CK) findings were used to confirm the lesion. Bone marrow biopsy was done and no bone marrow involvement was found. She did not receive chemotherapy and radiotherapy after surgery. No recurrence has been noted in the 22 months to date.