Due to the existence of the truly specific tumor antigen idiotype in multiple myeloma and based on encouraging data from dendritic cell vaccinated B-cell non-Hodgkin's lymphoma (NHL) patients, dendritic cell-based vaccination was first initiated in myeloma patients in 1995. This overview will summarize published and ongoing clinical trials in patients with multiple myeloma who are treated with idiotype-based dendritic cell (Id/DC) vaccination. All groups of investigators have found that Id/DC vaccination of multiple-myeloma patients is feasible and that myeloma-specific immunity can be induced in heavily pretreated individuals. In future trials, new dendritic cell-based immunization strategies will be investigated based on techniques like RNA transfection of DC.