The cosmetic and functional results of breast conserving therapy were evaluated in a sample of 76 patients with early stage breast cancer, treated by wide local excision, axillary dissection and postoperative radiotherapy between 1975 and 1985. A comparison was made between patients' ratings, independent ratings by two observers (an oncology nurse and a radiation oncologist) and objective measurements. In approximately 40% of the cases, moderate to large differences in the appearance of the treated versus the untreated breast were reported by patients and clinical observers alike. When evaluated on an individual level, the observers' ratings showed relatively high inter-rater agreement (kappa = 0.64), but low levels of concordance were found between the patients' and observers' ratings (kappa < 0.10). Approximately half of the patients reported limited arm or shoulder function, generally mild in nature. Compared to the patients', the observers' ratings of arm edema were significantly lower, indicating 20% mild and 5% more severe swelling. Objective measures of cosmesis and function correlated moderately with the observers' and patients' ratings. Both cosmetic and functional results were found to be significantly related to time elapsed since treatment, with patients treated longer ago exhibiting more problems. The cosmetic and functional outcomes were not related to the patients' age. The results suggest that the patients' opinion can provide important additional information in the evaluation of cosmetic and functional results of breast conserving treatment.