Docetaxel and cyclophosphamide (TC) and epirubicin and cyclophosphamide (EC) therapies are postoperative chemotherapy regimens for breast cancer. However, a previous study reported on the development of adverse events, such as neutropenia, in Asian patients. In this study, we examined the occurrence of neutropenia during chemotherapy, assessed the symptoms, and investigated the dose-reduction/discontinuation of chemotherapy or admission in patients undergoing postoperative EC or TC therapy following breast cancer surgery at our hospital between April 2018 and March 2020. EC and TC therapies were performed in 29 and 23 patients, respectively. We observed a significant difference in the incidence of neutropenia between the two therapies, although this observation might have been influenced by the frequent use of pegfilgrastim. In the TC therapy group, edema and pain were frequently observed. We observed no significant differences in the dose-reduction/discontinuation of chemotherapy or admission. However, in the TC therapy group, 5 patients required admission.