Purpose: The concurrent regimen of docetaxel, doxorubicin, and cyclophosphamide (TAC) has been categorized as a high-risk factor for febrile neutropenia (FN). The incidence of FN was reported to be as high as 17%-26% in studies conducted in Western countries. However, these rates may vary among different ethnic groups. This study aimed to evaluate the incidence of FN and its effect on prognosis following adjuvant TAC chemotherapy in Korean patients with advanced breast cancer. Methods: We analyzed data from 187 patients who received 6 cycles of adjuvant TAC chemotherapy between July 2005 and December 2014. No patients received long-acting granulocyte-colony stimulating factor (G-CSF) as primary prophylaxis for FN due to guidelines for cost reimbursement in Korea. The incidence rates of FN, dose reduction of TAC, relative dose intensity (RDI), relapse-free survival (RFS), and overall survival (OS) were investigated. Results: A total of 102 (54.5%) patients experienced FN, especially older patients (51 years vs. 49 years, p= 0.045). RDI was lower in patients with FN than in those without (96.4% vs. 99.5%, p= 0.001, respectively). Death was reported in 2 patients (2.35%) without FN and in 10 patients (9.80%) with FN (hazard ratio [HR]: 6.64; 95% confidence interval [CI]: 1.28 to 34.36; p= 0.024). No significant differences in RFS (p= 0.235) were found using Kaplan-Meier analysis. Conclusion: The incidence of FN was significantly higher in Korea than in Western countries, and FN had a negative impact on the patients' prognosis. Primary prophylactic G-CSF should be prioritized in Korean patients with advanced breast cancer who receive adjuvant TAC chemotherapy.