Women with a breast cancer diagnosis often are given a choice between breast conservation or mastectomy as the primary treatment for their cancer. Despite the high frequency of this cancer, there is little systemic information about the effect of surgical treatment on the quality of life or psychological adjustment of the patient. In this study, the authors prospectively evaluated quality of life, performance status, and psychological adjustment in 109 women who had primary breast cancer treatment. During the year of follow-up, no statistically significant differences in quality of life, mood disturbance, performance status, or global adjustment were found between the two surgical groups, and both groups of patients improved significantly during the year of observation (P = 0.0001). As was predicted, patients receiving mastectomy reported more difficulties with clothing and body image; however, these results apparently did not affect the assessment of mood or quality of life. The authors conclude that patients receiving breast conservation therapy do not experience significantly better quality of life or mood than patients having mastectomy; however, patients having breast conservation surgery have fewer problems with clothing and body image. Women receiving breast conservation therapy may require more intensive psychosocial intervention in the postoperative period because of the added burden of primary radiation therapy.