Purpose: Higher neutrophil-lymphocyte ratio (NLRs) indicate a pro-inflammatory state and are associated with poor survival. Conversely, higher albumin-globulin ratio (AGRs) may be associated with improved prognosis. We aimed to investigate the association between NLR and AGR and prognosis and survival in patients with breast cancer. Methods: This retrospective study included all patients with stage I–III breast cancer between 2011 and 2017 in Singapore General Hospital and National Cancer Center Singapore.Multivariate logistic regression analysis of NLR, AGR, age, stage, grade, and subtype was performed. Survival data between groups were compared using Cox regression analysis and log-rank tests. Results: A total of 1,188 patients were included, of whom 323 received neoadjuvant chemotherapy (NACT) and 865 underwent upfront surgery. In patients who underwent NACT, a higher AGR was significantly associated with a higher pCR rate (cut-off > 1.28; odds ratio [OR], 2.03; 95% confidence interval [CI], 1.13–3.74; p = 0.020), better DFS (cut off > 1.55; hazard ratio [HR], 0.37; 95% CI, 0.16–0.85; p = 0.019), and better CSS (cut off > 1.46; HR, 0.39; 95% CI, 0.17–0.92; p = 0.031). Higher NLR was significantly associated with worse DFS (cut off > 4.09; HR, 1.77; 95% CI, 1.07–2.91; p = 0.026) and worse CSS (cut off > 4.09; HR, 1.98; 95% CI, 1.11–3.53; p = 0.021). In patients who underwent upfront surgery, higher AGR correlated with significantly better OS (cut off > 1.17; HR, 0.54; 95% CI, 0.36–0.82; p = 0.004) and higher NLR correlated with worse OS (cut off > 2.38; HR, 1.63; 95% CI, 1.09–2.44; p = 0.018). Conclusion NLR and AGR are useful in predicting the response to NACT as well as prognosis of patients with breast cancer. Further studies are needed to explore their value in clinical decision making.