Background <p>MicroRNAs play a crucial regulatory function in preserving bone remodeling balance and bone metabolic homeostasis.</p> Aims <p>This study aimed to detect miR-202-5p expression in OP patients and investigate its role and potential regulatory mechanism in OP development.</p> Methods <p>qRT-PCR was used to determine miR-202-5p and PTEN expression in serum. The receiver operating characteristic curve was utilized to evaluate miR-202-5p’s diagnostic value for OP. CCK-8 and flow cytometry were applied to determine the effects of miR-202-5p on the proliferation and apoptosis of human fetal osteoblasts. Luciferase reporter assay was conducted to verify the targeted binding between miR-202-5p and PTEN.</p> Results <p>miR-202-5p in OP patients was markedly downregulated, and miR-202-5p exhibited high diagnostic value for OP. In vitro experiments showed that miR-202-5p promoted hFOB proliferation, inhibited apoptosis, and enhanced osteogenic differentiation. PTEN expression was significantly higher in OP patients. Prediction via the miRDB database indicated that PTEN might be a target gene of miR-202-5p, which was further confirmed by luciferase assay, verifying their interaction. Additionally, downregulation of PTEN significantly promoted osteogenic differentiation.</p> Conclusions <p>miR-202-5p holds promise as a novel potential diagnostic biomarker for OP. miR-202-5p may regulate osteoblast proliferation, apoptosis, and osteogenic differentiation by targeting PTEN, thereby exerting a role in OP.</p>