OBJECTIVES: Colon cancer is one of the most common malignancies in developed countries. Surgery is the primary treatment modality for this disease. However, by the time the patient presents with recurrent symptoms, the disease is rarely curable by surgery even when combined with other therapy.The aim was to assess the clinical and economic outcomes of OncoVAX(r). therapy in stage II colon cancer patients. METHODS: We have completed a prospectively randomized, controlled clinical trial of patients with Stage II colon cancer with active specific immunotherapy (ASI) using autologous tumor cell with an immunomodulating adjuvant bacillus Callmette-Guérin (BCG) vaccine (OncoVAX) in an adjuvant setting. Patients were randomized to either a control group or (OncoVAX) therapy, after surgical resection of the primary tumor and stratification by stage of disease. The cost analysis consisted of the direct health care costs. For the model, the costs and probabilities of the several interventions, disease stages and follow-up have been calculated. Survival and recurrence free survival were used from the clinical study. Utility values were derived from the literature. RESULTS: OncoVAX significantly improved survival and recurrence-free survival. The number of life years in the OncoVAX group amounted to 6.96 and in the control group 6.17. The number of recurrence-free life years gained is approximately 1.14 more in the OncoVAX group. The average costs per patient in the OncoVAX group amounted to US$20,395 and in the control group US$4,958. The costs per life year gained amounted to US$19,541 and the costs per QALY amounted to US$20,489. The total discounted cost-effectiveness ratio was US$22,660 and the discounted cost-utility ratio amounted to US$23,675 (discount rate: 4%). CONCLUSION: This study shows that OncoVAX is an effective treatment modality for patients with stage II colon cancer with a cost-effectiveness ratio in the range of other oncological treatments.