Aim: Breast cancer (BC) remains the most common malignant disease among women in Ukraine and worldwide. The indication for neoadjuvant hormone therapy (NAHT) is HR+/HER2- breast cancer of stage II-III. However, there are currently insufficient data on its impact on the IHC biological characteristics of tumors and clinical outcomes. Materials and Methods: The study was conducted at the Uzhhorod Treatment and Diagnostic Oncology Center during 2015–2023. At the diagnostic stage, morphological verification and IHC profile were determined based on trephine biopsy material. The study included 28 patients with HR+/HER2- BC, aged from 38 to 75 years old. All patients were prescribed NAHT with the use of aromatase inhibitors for 6.10±2.23 months. The expression levels of ER, PR, Ki-67, category G were assessed before and after NAHT using histological and IHC analyses. Results: After NAHT, we observed a decrease in Ki-67 levels from 25.31% to 10.25%, ER expression levels from 97% to 84%, and PR expression levels from 87% to 11%. There were changes in category G: G1 was observed in 45.83% of patients, G2 in 54.17%. The staging of BC also decreased. A moderate degree of curative tumor pathomorphosis was achieved in 76.47% of patients, and complete regression (pCR) in 5.88%. Conclusions: Neoadjuvant hormone therapy demonstrated high efficacy in the treatment of patients with luminal HR+/HER2- BC of stage II-III. In most cases, it was possible to reduce the proliferative activity of the tumor, which was accompanied by a decrease in tumor staging. This made it possible to perform organ-preserving surgeries in 60.71%, which confirms the feasibility of using NAHT as an alternative to chemotherapy in certain groups of patients.