Chronic endometritis (CE) is the most significant endometrial disease in terms of its impact on reproductive potential. Thus far, pathogenetically significant inflammatory markers — cytokines, inflammatory proteins, and hematological indices — have not been widely used in medical practice for the diagnosis of CE. This study aimed to evaluate indicators of systemic inflammation, including hematological parameters and inflammatory indices, in patients with infertility, and to determine their diagnostic significance for CE. We analyzed the data of examinations of 50 patients with infertility. The standard hematological method was used to determine the leukocyte count. Based on the blood cell composition, we calculated the inflammatory indices NLR, MLR, PLR, and SII. The concentration of CRP in the blood serum was determined by enzyme immunoassay. In patients with CE-associated infertility, the absolute and relative numbers of lymphocytes were lower (p = 0.0451 and p = 0.0089, respectively), whereas the relative numbers of monocytes and basophils were higher (p = 0.0469 and p = 0.0005, respectively) than in patients without CE. In the study group, the concentration of CRP in the blood was almost four times higher than in the control group (p = 0.0191), but all indicators remained within the normal range. A comparative analysis of the NLR, MLR, PLR, and SII indices revealed their significant growth in CE-associated infertility cases (p = 0.0387, p = 0.0058, p = 0.0335, and p = 0.0333, respectively). ROC analysis established the predictive significance of NLR (0.871 (95% CI: 0.767–0.974); p < 0.0001) and MLR (0.848 (95% CI: 0.737–0.958); p < 0.0001) indices for detecting CE in infertility patients.