Breast cancers have the highest incidence in women, and the mortality rate is high. Neutrophils and lymphocytes are the most common inflammatory cells. Clinically, neutrophil to lymphocyte ratio (NLR) is easy to obtain and the cost is low. It has been proved that NLR is closely related to the occurrence and development of various cancers. The NLR has been widely used in breast cancer research. It not only has guiding significance for the diagnosis of breast cancer, but also helps evaluate the clinical stage of breast cancer patients. Moreover, high preoperative NLR is associated with poor prognosis. However, whether NLR can be used as a predictive indicator of pathological complete response (pCR) of triple negative breast cancer (TNBC) is still controversial.