Purpose: This study aimed to evaluate weight changes in women during the period of TAC (docetaxel-doxorubicin-cyclophosphamide) chemotherapy after breast surgery and the differences in weight changes by disease characteristics among Korean women with breast cancer. Methods: The design of this study was retrospective survey research. The subjects of this study were 130 patients with fully completed TAC chemotherapy between January 2012 and April 2015. Body weight before their operation, and at 3 weeks, 6 weeks, 9 weeks, 12 weeks, 15 weeks, and 18 weeks after surgery, as well as general and disease characteristics, were reviewed via their medical charts. Results: The mean age of the patients was 51.2 years. The preoperative (baseline) mean weight was 59.4±8.44. Significant weight losses were observed in the initial (1st 3 week) period of TAC chemotherapy compared to the baseline and significant weight losses were observed with the exception of the period 6 weeks after breast surgery. There were significant differences in mean weight changes according to the stage of breast cancer, radiotherapy, and hormone therapy among disease characteristics. Conclusion: It is necessary to study weight changes after breast surgery for the long periods of TAC chemotherapy. Through the accumulated results of studies, nursing programs for breast cancer patients must be developed for the prevention of weight gain in the periods of TAC chemotherapy.