Objective: The purpose of this study was to investigate the role of fibulin-5 in the transforming growth factor beta (TGF-\beta)/Smad signaling pathway by measuring the differential expression of fibulin-5, TGF-\beta, and Smad2/3 in the connective tissue of the vaginal anterior wall of Uyghur women with pelvic organ prolapse (POP). Methods: Thirty-six Uyghur patients diagnosed with POP, who were admitted to the First Affiliated Hospital of Xinjiang Medical University from March 2015 to June 2018, were enrolled in the study. In the same period, 15 patients with benign uterine hysterectomy were included in the control group. The relative protein expression levels of fibulin-5, Smad2/3, TGF-\beta1, TGF-\betaRI, and TGF-\betaRII in the anterior vaginal wall of each group were determined by immunohistochemistry, quantitative PCR, and Western blotting. Results: Immunohistochemistry showed that the expression levels of Smad2/3, fibulin-5, TGF-\beta1, TGF-\betaRI, and TGF-\betaRII were significantly lower in the POP group than in the control group (P 0.05). RT-PCR showed that the mRNA expression levels of TGF-\beta1, TGF-\betaRI, TGF-\betaRII, and fibulin-5 were significantly lower in the POP group, with statistical significance (P 0.05), whereas the expression of Smad2 and Smad3 decreased, but without statistical significance (P > 0.05). Western blot analysis showed that the expression of TGF-\beta1, TGF-\betaRI, TGF-\betaRII, fibulin-5, and phosphorylated Smad2/3 was significantly lower in the POP group than in the control group (P 0.05), but there was no difference in Smad2/3 protein expression compared with the control (P > 0.05). Conclusion: The amount of functional elastic fibers in the pelvic connective tissue structure of POP patients decreased via involvement of the TGF-\beta/Smad signaling pathway. Future studies are needed to confirm the pathogenesis of POP.