Plasmablastic lymphoma (PBL) is a rare and aggressive form of large B-cell lymphoma (LBCL) most commonly seen in the setting of chronic immunosuppression or autoimmune disease. The prognosis is poor and CHOP-like regimens often fail to produce durable remission; therefore, there is no established standard of care treatment. However, PBL demonstrates substantial morphologic and immunophenotypic overlap with multiple myeloma (MM), suggesting that MM therapeutics might prove useful in treating PBL. We studied the effects of treatment using the first-in-class monoclonal antibody directed against CD38, daratumumab, in combination with chemotherapy in seven patients with advanced-stage LBCL with plasmablastic features. Treatment was safe and well-tolerated. Among six evaluable patients, six patients had complete response after treatment, and four patients who met strict WHO criteria for PBL had durable response (12–31 months and ongoing).