The oncogenic miR-21 has been widely recognized to promote the development and progression of various types of malignant tumors, but not cervical cancers. The aim of this study was to examine the expression of miR-21 and PTEN in cervical cancer specimens using quantitative PCR. The miR-21 level was then manipulated in the cervical cancer lines and the regulation of miR-21 on the proliferation, migration and invasion of cervical cancer cells was determined. Additionally, we determined the role of PTEN in the miR-21-regulated proliferation, migration and invasion of cervical cancer cells. miR-21 was upregulated in the cervical cancer specimens, negatively correlating with the PTEN mRNA level. Transfection of the miR-21 mimics was markedly promoted, whereas the miR-21 inhibitor suppressed the proliferation, migration and invasion of cervical cancer cells, with a significant inhibition of PTEN expression. In addition, the overexpression of PTEN markedly inhibited the proliferation and migration of the cervical cancer cells. The present study showed the upregulation of miR-21 in invasive cervical cancers, and confirmed the promotion of miR-21 with regard to the proliferation, migration and invasion in cervical cancer cells via inhibiting the PTEN expression. To the best of our knowledge, this is the first study to confirm that the miR-21/PTEN pathway promotes cervical cancer.