Cutaneous malignant Lymphoma in infancy is rare. The majority of these tumors present nonB - nonT cell phenothype. Recently, we encountered an infant with cutaneous malignant Lymphoma, which was a B-cell tumor in origin. The patient was a 23 month old female and she came to our Clinic on July, 1992. Seven months previously, her mother noticed a tumor on the back which was considered a sebaceous cyst and then an angioms. Her general conditions was good. Since the lesion increased, the baby got into Hospital. On physical examination a violet, dome-shaped, indolent and movable nodular cutaneous tumor was confined to a circumscribed area of the skin, in left subscapolar region, about 3×2 cm in size. Systemic lymphadenopathy and splenomegaly were not present. The tumor was radically removed and the histological diagnosis was: High grade non Hodgkin, diffuse lymphoma, non Burkitt, with small non clived cells, according to Working Formulation. The neoplastic infiltrate react with CD 45R, CD 45RA, CD 20, CD43 and failed to react with CD30, CD 45RO, confirming the B cell phenotype. Bone marrow aspirate revealed no evidecence of involvement by tumor cells. After staging investigations, following Murphy's criteris, the patient was treated with two blocks of therapy, according to AIEOP Non Hodgkin Lymphoma 92 Protocol (DEXA, MTX-MD, IFO, VP16,ARA-C + DEXA, CPM, MTX – MD, ADR). After 19 months, there is no evidence of local recurrence or dissemination.