Background Febrile neutropenia (FN) is a life-threatening complication of Docetaxel-based chemotherapy regimens (DBRs). Prophylactic granulocyte-colony stimulating factor (G-CSF) can reduce the risk of FN. This study investigated the effect of G-CSF on FN in patients receiving DBRs for breast cancer. Methods Patients treated between 2015 and 2017 were identified from the hospital’s pharmacy database and their medical records were examined retrospectively. Data from patients’ first four cycles of DBR were collected. FN rate, FN associated length of hospital stay (FN-LOS), and chemotherapy dose modification/delay due to FN were compared between patients who did (G-CSF group) or did not (non-GCSF group) receive prophylactic G-CSF. Results Of the 276 included patients, 83.3% received a DBR as adjuvant or neoadjuvant therapy, and 50% received docetaxel as combination therapy. Prophylactic G-CSF was administered with the first cycle of a DBR in 69.9% of patients who were significantly less likely to experience FN compared to the non-G-CSF group (6.2% vs. 15.7%; odds ratio: 0.36 95% CI: 0.16–0.82; p = 0.020). Collectively and after the 4 DBR treatment cycles, FN rate (4.8 vs. 8.5; odds ratio: 0.54 95% CI: 0.30–0.97; p = 0.043) and the mean FN-LOS (3.55 vs. 5.28 days; t = –2.22; p = 0.037) were reduced in the G-CSF group. There was no difference in DBR dose delay/reduction between both groups in cycles 2–4. Conclusion In patients receiving DBRs for breast cancer, prophylactic G-CSF significantly reduced both the rate of FN and duration of hospitalization for FN.