Anemia, which is a common problem in cancer patients, has a negative effect on survival by decreasing the efficacy of chemotherapy and particularly of radiotherapy, as well as impairing the quality of life (QoL) of patients. Recombinant human erythropoietin (rHuEPO) decreases a patient's need for transfusions and increases their QoL. The aim of this study was to evaluate the effect of weekly single-dose EPO treatment on transfusion rates, QoL, and hemoglobin (Hb) levels. In addition, patients were followed up for a long period to assess the impact of EPO treatment on survival. The study was conducted from December 2001 to December 2002 in patients with newly diagnosed lymphoma or solid tumors using a prospective and controlled design. EPO-β was given as a single dose of 450 U/kg once a week for 12 weeks. The study and control groups included 16 patients each. Hb levels measured in the study group at the 4th, 8th, and 12th weeks were significantly higher than the values recorded before the start of chemotherapy. In the control group, Hb levels post chemotherapy were significantly lower than values recorded prior to treatment. The increased Hb levels in the study group were significant at the 8th and 12th weeks of treatment compared to levels measured prior to treatment. In the control group, Hb levels at the 4th and 8th weeks were significantly lower than pretreatment levels. When the percent increase of Hb levels of the study and control groups with respect to treatment week was compared, the difference was statistically significant at the 4th, 8th, and 12th weeks. Although the increase on the performance scale within each group during treatment was significant in both the study and control groups, the increase was more marked in the study group. The percent increase on the performance scale with respect to week of treatment was higher in the study group than in the control group. In EPO treatment group, side effects were seen in 38% of patients, with 19% being local pain in the injection area, 13% local hyperemia, and 6% headache. The mean follow-up period of the study and control group was 7.03 ± 0.41 (6.0-7.41) and 7.46 ± 0.45 (6.58-7.83) years, respectively; no statistically significant difference existed between these figures. Overall survival at the end of 7 years of follow-up was 68.8% and 81.3% for the study and control groups, respectively. The use of EPO-β in lymphoma and solid tumor patients on a once-weekly regimen (450 U/kg) was determined to be effective in increasing Hb levels, decreasing transfusion rates, and improving QoL. This regimen was safe, did not cause serious side effects, and can be recommended because of its high patient compliance and tolerability. An effect of EPO on prognosis was not evident. We could not have an explanation on the effect of EPO treatment on prognosis, as there were low number of patients and advanced-staged patients died earlier. Therefore, a larger number of patients are needed to clarify the effect of EPO treatment on prognosis.