Background: Breast cancer is a major health problem all over the world. Neutrophil-to-lymphocyte ratio (NLR) is an easy, cost-effective, readily available diagnostic tool for systemic inflammation. Aim: We aimed to evaluate whether baseline peripheral neutrophils to lymphocytes ratio in the peripheral blood of breast cancer patients are correlated with pathological complete response (pCR) following neoadjuvant. chemotherapy. Patients & Methods: This Observational prospective cohort study was carried out in the Clinical Oncology Department, Helwan University Hospitals from October 2022 to September 2023. The study involved 50 females with breast cancer who underwent treatment with neoadjuvant. chemotherapy protocol. Results: In this study, 17 patients (34%) achieved statistically significant pCR following neoadjuvant chemotherapy among the patients with lower NLR as compared to the patients with high NLR. Our study showed also that 12 (66.7%) patients in the lower NLR (<1.69) achieved pCR, while only 5 (15.6%) patients in the high NLR (≥1.69) achieved pCR (P value=0.002). Conclusion: Lower baseline peripheral NLR is associated with better rates of pCR in breast cancer patients receiving neoadjuvant chemotherapy, reflecting better treatment outcomes.