PURPOSE: A patient decision aid for the surgical treatment of early stage breast cancer was developed and evaluated. The rationale for its development was the knowledge that breast conserving therapy (lumpectomy followed by breast radiation) and mastectomy produce equivalent outcomes, and the current general agreement that the decision for the type of surgery should rest with the patient. METHODS: A decision aid was developed and evaluated in sequential pilot studies of 18 and 10 women with newly diagnosed breast cancer who were facing a decision for breast conserving therapy or mastectomy. Both qualitative (general reaction, self-reported anxiety, clarity, satisfaction) and quantitative (knowledge and decisional conflict) measures were assessed. RESULTS: The decision aid consists of an audiotape and workbook and takes 36 min to complete. Based on qualitative comments and satisfaction ratings, 17 of 18 women reported a positive reaction to the decision aid, and all 18 reported that it helped clarify information given by the surgeon. Women did not report an increase in anxiety and 17 of 18 women were either satisfied or very satisfied with the decision aid. CONCLUSION: This pilot study supports the hypothesis that this decision aid may be a helpful adjunct in the decision for surgical management of early stage breast cancer. We are currently conducting a randomized trial of the decision aid versus a simple educational pamphlet to evaluate its efficacy as measured by knowledge, decisional conflict, anxiety and post-decisional regret.