The current study aims to evaluate the expression of miR-3142 in the serum of cervical cancer patients and healthy controls, thereby exploring the role of miR-3142 in the diagnosis and prognosis prediction of cervical cancer. Real time PCR analysis was carried out to evaluate the expression of miR-3142 in the serum and tissues of cervical cancer patients. The diagnostic threshold and the area under the curve (AUC) were analyzed by receiver operating characteristic curve (ROC) and the survival analysis was performed by Kaplan-Meier. Our data showed that the expression of miR-3142 in cervical cancer tissues was significantly higher than that in adjacent tissues. In addition, the expression of miR-3142 was significantly higher in patients with stage II/ III cervical cancer and lymph node metastasis than in patients with stage I and lymph node metastasis. Meanwhile, the expression of miR-3142 was not significantly correlated with age and differentiation degree, but positively correlated with tumor size, FIGO stage, lymph node metastasis, and depth of stromal invasion. ROC curve analysis showed that sensitivity and specificity were 86.2% and 100%, respectively. Kaplan-Meier analysis showed that the higher expression of miR-3142 predicted poor prognosis. In summary, serum miR-3142 in cervical cancer is increased and is closely related to the occurrence and development of cervical cancer, which can be used as a diagnostic and prognostic marker of cervical cancer.