Thirty-two patients with Stage I or II breast cancer who had completed conservative breast-preserving treatment were asked to rate their cosmetic outcomes. Within this group, extent of the surgical excision of the breast tumor varied, with biopsy scars ranging from 2 to 19.5 cm. All patients had received external beam radiotherapy, with local boost doses in 17 cases. The average interval between self-evaluation and the completion of radiotherapy was 19 months. Patients completed a questionnaire rating the appearance of the treated breast, the degree of difference between breasts and overall satisfaction with cosmesis. They were asked to describe differences between breasts and to make any additional comments. Appearance of the treated breast was rated good to excellent by 94%, although 88% noted a difference of slight to moderate degree between treated and untreated breasts. Overall, 78% of patients were very to extremely satisfied, while moderate satisfaction was reported by 19%. Reports of breast differences included reduced size of the treated breast (44%), increased firmness (31%), elevation (25%), and skin color changes (22%). Reasons for dissatisfaction included chronic breast pain in 3 patients, breast edema in one and arm edema in one. Two patients wanted the untreated breast reduced in size. Statistically significant inverse relationships were found between the length of the biopsy scar and patient ratings of both appearance of the treated breast and overall satisfaction. These results indicated that although most patients were satisfied with cosmetic results of breast-preserving treatments, they are quite discriminating in their evaluations of differences between breasts. Functional factors such as pain and edema had a negative impact on satisfaction with cosmesis.