Background. Breast cancer is the leading cancer type in women. Improvement in its management requires a continuous investigation of new tools for diagnosis and treatment. Biomarkers for breast cancer remain a field of great interest, despite existing knowledge. Extensive research recognizes the critical role played by tumor-infiltrating lymphocytes (TILs) in terms of prognosis and prediction, but much uncertainty still exists about the application of this biomarker in clinical practice. Thus, the purpose of this paper is to review recent researches about the role of TILs as a prognostic and predictive factor in the clinical management of breast cancer subtypes. Materials and methods. Eligible studies from Medline, Pubmed, Google Scholar (2010–2020) databases were analyzed and retrieved. Results. For primary tumors, a positive correlation was found between TILs and survival prognosis for HER2+ and TNBC subtypes, while for luminal subtypes it was a negative correlation. The predictive value of TILs in the neoadjuvant setting is established for HER2+, TNBC subtypes. In the case of using TILs as a predictive factor for HER2-targeted therapy, it remains a concern due to controversial data. For residual tumor, it is growing body of evidence about the positive correlation of TILs and prognosis for all subtypes, but data are limited. Conclusions. TILs were found to have prognostic and predictive value. However, due to the heterogeneity of breast cancer subtypes, TILs as a biomarker should be interpreted with caution. Further studies need to be carried out to determine the validity of making a clinical decision based on TILs count.