Tumor load reduction has an influence on survival of patients in the chronic phase of chronic myelogenous leukemia (CML). This comprises both reduction of white blood cell (WBC) mass and reduction of the Philadelphia (Ph)-positive clone. Besides drug monotherapy, intensive combination chemotherapy is also very effective in reducing tumor burden in the chronic phase of CML. Therapeutic concepts consisting of combination chemotherapy include intensive chemotherapy alone or in combination with interferon-alpha (IFN-alpha) and preparative regimens before autografting or allografting. All these concepts demonstrate the effectiveness of this treatment form. The high toxicity of combination chemotherapy does not justify its application in unselected patients. However, in suitable patients, possibly in poor interferon-alpha responders (as carried out in the current German CML study) it might be superior with regard to survival.