African American (AA) females with endometrial carcinoma have a significantly worse prognosis with regard to disease-free survival and overall survival than their European American (EA) counterparts and this finding is true across all stages and grades. The presence of tumor-infiltrating lymphocytes (TILs) has been demonstrated to be of prognostic significance in a variety of malignancies, including endometrial cancers. This study aims to determine whether clinically significant differences in levels of CD8+ cytotoxic T lymphocytes, FoxP3+ regulatory T lymphocytes, and CD45RO+ memory T lymphocytes exist between races and to document the clinical impact of TILs. One hundred ten patients with endometrial adenocarcinoma, treated with hysterectomy from 2003 to 2011 were studied. Patients were selected to provide equal representation across type and grade for both EAs and AAs. Immunohistochemical stains were used to highlight CD8-positive, FoxP3-positive, and CD45RO-positive TILs at the endometrial-myometrial interface on slides from paraffin-embedded tissue. Patients with "high" or "low" levels of TILs were compared with respect to the race, tumor type, and survival. High levels of CD45RO+ TILs were associated with improved overall survival in EA women (hazard ratio, 0.32; 95% confidence interval, 0.11-0.92; P=0.034). Comparatively, AA women with high levels of CD45RO+ TILs received no survival benefit (hazard ratio, 0.96; 95% confidence interval, 0.35-2.64; P=0.94). High levels of CD8-positive or FoxP3-positive TILs, alone, had no impact on survival. EA patients with TILs containing high levels of CD45RO cells but low levels of CD8+ cells lost the survival benefit; however, limited numbers preclude significant conclusions from this observation. Neither tumor type nor race were predictive of the levels of TILs of any type. Further study with a larger sample size is required to determine the impact of TIL subtype combinations on survival.