Background: Breast reconstruction after skin-sparing mastectomy for breast cancer (BC) is an important rehabilitation stage. Its results depend on many factors, with the immune system status playing the main role. The purpose of this study was to identify characteristics of the local lymphocyte populations in patients with breast cancer in the early postoperative period after reconstructive surgery with textured implants (TI). Methods: The study included 30 patients aged 32-68 years, mean age 42.9±1.98 years, with stage I-IIb BC (monocentric nodular BC, T1N0M0 - T2N1M0). All patients underwent skin-sparing mastectomy with level II axillary lymph node dissection and immediate implant reconstruction in 2017-2019. Populations and subpopulations of lymphocytes were determined in wound fluid from the cavity with TI on days 1, 3-4 and 7 after the surgery using the FacsCanto II flow cytometer (Becton Dickinson, USA) with markers: CD3 FITC /CD15+56 PE /CD45 PerCP /CD4 PE-Cy7/CD19 APC/ CD8 APC-Cy7; CD45RA FITC /CD45RO PE /CD3 PerCP /CD8 APC; CD45RA FITC /CD62L PE /CD3 PerCP /CD4 APC; CD4 FITC /CD127 PE /CD3 PerCP / CD25 APC-Cy7; CD4 FITC /CD38PE /CD3 PerCP / HLADR APC. At least 50,000 cells were accumulated in each sample for the analysis. Results: The relative number of total lymphocytes exceeded the initial values by 3.3 (p=0.025) and 10.9 (p=0.012) times, respectively, on days 3-4 and 7 after surgery. Levels of CD3+CD4+ cells increased gradually and were 29% (p=0.042) higher by day 7, while levels of CD3+CD8+ decreased during the whole observation period. Levels of Tregs did not change, while B lymphocytes decreased by 36% (p=0.035) and 67% (p=0.026), respectively, on days 3-4 and 7. The levels of activated T lymphocytes increased by 33% (p=0.038) on days 3-4, compared with the initial values, probably due to the elevation of CD3+CD8+ levels (by 32%, p=0.037). The number of activated T lymphocytes with the CD3+CD4+ phenotype increased by 44% (p=0.024) on days 6-7. While the content of CD3+CD4+ cells with early activation markers (CD38+) significantly decreased (by 40%, p=0.031) and remained the same on days 3-4 and 7, the number of CD3+CD8+ with similar markers (CD38+) significantly increased by 28% (p=0.044) and 43%. Conclusions: TI implantation was accompanied by the activation of the cytotoxic T unit during the observation period, together with a decrease in immunosuppressive populations of lymphocytes, which may indicate a favorable development of the patient's body reaction.