Breast cancer is still a significant health problem in the world, with chemotherapy as an essential component in its management. Limited research on tumor- infiltrating lymphocytes (TIL) as a biomarker for the effectiveness of breast cancer treatment was conducted and is still contradictory. This study aims to investigate the relationship between TILs and the clinical response to neoadjuvant chemotherapy in breast cancer. The research used a cross-sectional study on eligible breast cancer patients in Wahidin Sudirohusodo Hospital in Makassar. TIL levels were grouped based on the histopathological examination results of breast tissue samples into three categories: low (0% to 10%), medium 15% to 50% and high (55% to 100%). Responsiveness was assessed based on changes in tumor size after neoadjuvant chemotherapy. The Chi-Square test is the primary analysis in this study. Results of 40 participants, the sample had a median age of 40 (27-73 years), mainly in the clinical stage III (40.0%), had moderate TIL concentration (47.5%), and was responsive to the neoadjuvant chemotherapy (87.5%). There was no significant association between TIL concentration and chemotherapy responsiveness (p > 0.05). However, in post-chemotherapy conditions, the median value of tumor size in the group with the high TIL category was significantly lower than in the low and medium TIL groups (p=0.034). There was no association between TIL levels and the clinical response to neoadjuvant chemotherapy in breast cancer patients. Further research is needed to confirm these findings.