Dendritic cells(DC) are most powerful antigen presenting cells for the induction of antigen specific T cell response. They have been successfully used in clinical pilot study to induce tumor specific immunity as well as clinical response in selected patients. Here we report the ability of DC therapy against chronic myelogenous leukemia(CML). Three patients with CML received a series of four infusions of CML-specific bcr/abl peptide-pulsed autologous DCs. Vaccination was well tolerated. No physical sign of autoimmunity was detected in any of patients. DC vaccination induced delayed-type hypersensitivity(DTH) reactivity toward KLH in all patients, as well as positive DTH reaction to peptide-pulsed DC in one patient. Clinical responses have been measured with no patients. Further studies are necessary to demonstrate clinical effectiveness and impact on the survival of CML patients.