Endometriosis is one of the common diseases of women, especially in reproductive age, and it is one of the most important causes of infertility in women. The aim of this study was to investigate the level of mRNA-TLR-5 expression in women with endometriosis. The present study was performed in Nikan Hospital, Tehran, Iran, in 2021. The samples of endometrial mucosa for the eutopic group and an ovarian endometriotic cyst for the ectopic group were obtained from the patients who underwent laparoscopic surgery at the Fetal Infertility Center and were diagnosed with endometriosis. Normal endometrial samples were also obtained from patients who had no history of infertility and underwent laparoscopic TL surgery for reasons other than endometriosis such as ovarian cysts (control group). After RNA extraction and cDNA synthesis, TLR-5 gene expression was evaluated by the Real-Time PCR method. Based on the results of the comparison of TLR-5 gene expression in all three ectopic, eutopic endometrium, and control groups by Real-Time PCR, it was found that the TLR-5 gene expression is significantly higher in ectopic samples than in the other two groups, but there is a significant difference between two utopic and control groups. The increase in TLR-5 expression in the ectopic group can probably be a reason for reducing the apoptosis of cells entered into the peritoneal cavity and creating an environment for the survival and proliferation of these cells.