HPV/pap tests are widely used for cervical cancer screening, playing a crucial role in early diagnosis and guiding future treatment options. However, approximately 50% of cervical cancer patients are diagnosed at an advanced stage, which is associated with higher recurrence rates and poorer survival outcomes than early-stage diagnoses. This underscores the need for effective treatments for advanced-stage cervical cancer. Among the various oncogenes implicated in cancer, PIK3CA expression is known to cause cervical cancer, suggesting that inhibiting PIK3CA may impede cervical cancer progression. In this study, we transfected PIK3CA-overexpressing tumor cells (SiHa, C33A, and HeLa) with miR-29a, a microRNA extensively studied as a therapeutic candidate for oncogene suppression in various tumor types. We conducted RT-qPCR and Western blot analyses to assess changes in PIK3CA expression at the RNA and protein levels. Wound healing and cell migration assays were used to evaluate the effects of miR-29a on cell division and migration in HeLa cells. We confirmed a reduction in PIK3CA expression at both RNA and protein levels following miR-29a transfection. After transfecting miR-29a into HeLa cells, we observed a reduction in cell division and migration, as demonstrated by wound healing and cell migration assays. Additionally, we found that miR-29a binds to the 3′-UTR region of PIK3CA, leading to a reduction in its gene expression. Furthermore, we correlated the concentration of miR-29a in clinical histologic biopsy samples from cervical cancer patients with disease progression. These findings indicate that miR-29a can slow the progression of cervical cancer by targeting PIK3CA and potentially aid in its treatment. miR-29a shows promise as a therapeutic agent for inhibiting oncogene expression and controlling cervical cancer progression, especially in advanced-stage cases.