PURPOSE: In order to improve the proper use of radiotherapy and breast-conserving treatment (BCT) in the management of breast cancer, current status of breast cancer treatment in Korea was surveyed nationwide and the use of BCT were evaluated. MATERIALS AND METHODS: Patients characteristics and treatment pattern of 1048 breast cancer patients from 27 institutions diagnosed between January, 1998 and June, 1998 were analyzed. The incidence of receiving BCT was analyzed according to the stage, age, geography, type of hospital, and the availability of radiotherapy facility. RESULTS: Radical mastectomy was performed in 64.8% of total patients and 26% of patients received breast- conserving surgery (BCS). The proportions of patients receiving BCT were 47.5% in stage 0, 54.4% in stage I, and 20.3% in stage II. Some of the patients (6.6% of stage I, 10.1% of stage II and 66.7% of stage III) not received radiotherapy after BCS. Only 45% of stage III patients received post-operative radiotherapy after radical mastectomy. The proportion of patients receiving BCT was different according to the geography and availability of radiotherapy facilities. CONCLUSION: Radiotherapy was not fully used in the management of breast cancer, even in the patients received breast-conserving surgery. The proportion of the patients who received BCT was lower than the report of western countries. To improve the application of proper management of breast cancer, every efforts such as a training of physicians, public education, and improving accessibility of radiotherapy facilities should be done. The factors predicting receipt of BCT were accessibility of radiotherapy facility and geography. Also, periodic survey like current research is warranted.