MicroRNAs (miRs) have been implicated in many aspects of tumor cell development and survival, including sensitivity to radiotherapy. In particular, miR-19a regulates the proliferation of cervical cancer cells, but its role in radiosensitivity is not known. Here, we describe the consequence of silencing miR-19a using antisense oligonucleotides (ASO) on the radiosensitivity of human cervical cancer SiHa cells.,Following transfection with miR-19a-ASO or control-ASO, SiHa cells were exposed to X-rays to determine their proliferation.,Silencing of miR-19a significantly improved the sensitivity of SiHa cells to radiotherapy by reducing proliferation, increasing apoptosis, upregulating BAX, and downregulating Bcl-2.,Overall, inhibiting miR-19a significantly improves the sensitivity of SiHa cells to radiotherapy, which could lead to new methods for the treatment of cervical cancer.