The costs of cancer treatment were estimated for five groups of cancer patients: those with operable breast cancer receiving adjuvant chemotherapy and patients with advanced breast cancer, ovarian cancer, germ cell cancer and small cell lung cancer. Cancer treatment costs were substantial but chemotherapy cost was a relatively minor item. Methods of limiting treatment costs are identified as reducing hospital stay, encouraging outpatient administration of chemotherapy and limiting the number of supernumary investigations. The cost of different cancer treatment options should be considered when management decisions are made.