In order to generate an immune response against myeloma cells in an homogenous murine model, a stable hybrid cell line (DCSp) was established through the syngenic fusion between mouse dendritic cells (DC) and mouse Sp2/0 myeloma cells. DCSp cells behaved as potent T cell stimulators and were able to induce Sp2/0 specific cytotoxicity. When mice were immunized with irradiated hybrids before SP2/0 injection, they exhibited a significantly higher rate of survival as compared with controls. When tumors were detected, their emergence was not delayed, and time elapsed between tumor clinical perception and death remained unchanged. A humoral immune response was also always associated. We assume that this stable dendritoma cell line can be considered a valuable tool for myeloma studies in an homogenous mouse model. The efficiency of dendritoma as a weapon against tumor cells and the benefit of syngeny in experimental models are discussed.