We report a rare case of primary splenic lymphoma (non-Hodgikin`s lymphoma, B cell type, follicular and diffuse type, grade 2/3). A 65-year-old woman visited our hospital without symptom, because of a splenic mass detected on the abdominal ultrasonography (US) of the regular annual health check. Repeated US at this hospital demonstrated two round mass lesions in the spleen, measuring 20mm and 6mm in diameter with hypoechoic lesion with less-distinct boundary echo; the enhanced abdominal computed tomography presented hypoperfusional lesions. Contrast-enhanced US (CEUS) showed ring enhancement with central perfusion defect in the early vascular phase, by Levovist, but diffuse homogenous iso-enhancement in the early vascular phase and washout defect with residual very fine enhanced spot in the late vascular phase, by Sonazoid. A positron emission tomography/computed tomography examination was done for evaluating the extent of the disease which showed pathologic increased 18F-fluorodeoxyglucose uptake in the spleen and the left axillar lymph nodes. These results suggested primary malignant lymphoma, most probable, so splenectomy was performed. The histopathological study of this resected specimen confirmed this diagnosis, and immunohistochemistry showed that tumor cells were CD3-, CD5-, CD10+, CD20+, bcl-2(-~focal), cyclinD1-. The splenic biopsy is so risky that the image diagnosis might be very important. This case don't have the typical echo pattern of malignant lymphoma (absence of internal echoes, presence of posterior echo enhancement) possibly due to the histological findings showing germinal center-like follicular pattern. The CEUS was, however, so useful to present characteristic echo enhancement pattern of malignant lymphoma.