This paper reports a descriptive study of the costs and quality of life (QoL) outcome of treatments for early stage breast cancer in a cohort of Australian women, one year after initial surgical treatment. Mastectomy without breast reconstruction is compared to breast conserving surgery and radiotherapy (breast conservation). Of the 397 women eligible for the study, costing data were collected for 81% and quality of life data for 73%. The cost differences between treatment groups were mainly accounted for by adjuvant therapies, the more expensive being radiotherapy. When compared to women treated by mastectomy, those treated by breast conservation reported better body image but worse physical function. The negative impact of breast cancer and its treatment was greater for younger women, across a number of dimensions of quality of life (regardless of treatment type). While this study shows that breast conservation is more expensive than mastectomy, the QoL results reinforce the importance of patient participation in treatment decisions.