Background: An easy, reproducible and simple marker is needed to estimate phase of endometrial pathologic lesions such as hyperplasia and endometrial cancer and distinguish from pathologically normal results. We here aimed to clarify associations among neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), endometrial hyperplasia and cancer in patients with abnormal uterine bleeding. Materials and Methods: Patients (n=161) who were admitted with abnormal uterine bleeding and the presence of endometrial cells on cervical cytology or thick endometrium were investigated. The study constituted of three groups according to pathologic diagnosis. Group 1 included endometrial precancerous lesions like hyperplasia (n=63), group 2 included endometrial cancerous lesions (n=38) and group 3 was a pathologically normal group (n=60). Blood samples were obtained just before the curettage procedure and the NLR was defined as the absolute neutrophil count divided by the absolute lymphocyte count; similarly, PLR was defined as the absolute platelet count divided by the absolute lymphocyte count. Results: The white blood cell count was significantly higher in patients with cancer than in those with hyperplasia (p=0.005). The platelet count and neutrophil to lymphocyte ratio were significantly higher in patients with cancer than in control patients, but there was significantly no difference between patients with hyperplasia and other groups (p=0.001 and p=0.025 respectively). PLR was significantly lower in control subjects than in other groups (p<0.001), but there was no significant difference between patients with hyperplasia and those with cancer. Conclusions: PLR was significantly lower in control subjects than in other groups. Thus both hyperplasia and cancer may be differentiated from pathologically normal patients by using PLR. White blood cell count was significantly higher in patients with cancer than in those with hyperplasia and pathologically normal patients. Therefore white blood cell count may be used for discriminate hyperplasia to cancer. By using multiple inflammation parameters, discrimination may be possible among endometrial cancer, endometrial precancerous lesions and pathologically normal patients.