Adjuvant chemotherapy (ACT) may expose patients to morbidity, with little gain in outcome. Treatment with CMF (cyclophosphamide, methotrexate, fluorouracil) has been the standard ACT in several countries for decades. In this model, efficacy, tolerability and quality of life data from the English-language literature were incorporated with Norwegian standard ACT practice and cost data in a cost-effectiveness/cost-utility approach. The CMF efficacy was calculated as 2.45 years saved per patient treated. The quality of life was assumed diminished by 0.33 (0-1 scale) for 6 months and the life years gained were valued Q = 0.86. An 85% dose intensity was employed, one British pound ( 1) was calculated as 12 NOK and a 5% discount rate was used. The total cost of adjuvant CMF, including amounts spent on drugs, administration, travelling and production loss, was calculated to 2365- 6253, depending on the method chosen. Money spent on drugs alone constituted 13-34%. The cost per life year saved was measured as 2170- 5737. A cost-utility approach revealed a cost per quality-adjusted life year (QALY) of 2973- 7860. Adjuvant CMF in breast cancer is cost-effective in Norway.