Lymphomas of the uterine cervix are uncommon neoplasms and typically appear as diffuse cervical enlargement. We describe a rare case of primary high-grade lymphoma of mucosa-associated lymphoid tissue of the uterine cervix in a 46-year-old white woman. The tumor, incidentally disclosed at gynecological examination, appeared as a single common polyp. Immunohistochemical investigation found the lesion to consist of a monomorphic CD20-positive infiltrate of large blasts and rare intermingling centrocyte-like lymphoid cells. A dense area of monotypic (lambda light-chain restriction) plasma cells was found beneath the endocervical mucosa; only a few scattered lymphoepithelial lesions were present. The neoplastic cells did not stain for CD5, CD10, CD23, CD43, or cyclin D1. A bone marrow biopsy displayed a paratrabecular, centrocyte-like B-cell infiltration, but no lymphadenopathy was detected by instrumental examination (computed tomographic scan, magnetic resonance imaging). The tumor was successfully treated by multiagent chemotherapy followed by total hysterectomy. To our knowledge, this case represents the second reported example of mucosa-associated lymphoid tissue-type lymphoma occurring in the uterine cervix. We highlight the very unusual gross appearance of this case and emphasize the difficulty of interpreting lymphoid infiltrates in the lower genital tract by microscopy.