We report the use of a new treatment modality in 2 patients with primary cutaneous B-cell lymphoma. In a 58-year-old woman with progressive nodular lesions on the scalp and face, several treatment attempts either failed or could not be used because of severe adverse effects and underlying epilepsy. The patient declined radiotherapy. A 30-year-old man presented with recurrence of tumor nodules occipitally, thoracically, on the arm, and on the right thigh after several excisions. Intralesional injection of rituximab, a chimeric antibody directed against the CD20 transmembrane antigen present in malignant and normal B cells, resulted in partial regression of tumor nodules. No adverse effects occurred except pain during or shortly after injection and, in one patient, a slight rise in body temperature. Due to the treatment a prolonged complete disappearance of B cells from peripheral blood samples was observed. Intralesional rituximab therapy is a nontoxic and effective treatment for cutaneous B-cell lymphoma that deserves further investigation in larger clinical trials.