--- - |2 Abstract Upregulated in lung cancer, miRNA‐182 was found to be related to cancer proliferation and chemoresistance. However, there is no report on the role of miR‐182 in radioresistance, which is a main obstacle of radiotherapy. In this study, we aimed to depict the effect of miR‐182 inhibition on cellular sensitivity to ionizing radiation. Our data confirmed that miR‐182 was upregulated in lung cancers and tissues and that miR‐182 was responsive to irradiation. We also showed that miR‐182 knockdown suppressed cell proliferation and increased cell apoptosis after irradiation. DNA damage remains unrepaired in miR‐182 knockdown cells, which results in cell cycle arrest. Finally, we found that FOXO3 is a direct target of miR‐182 and that overexpression of FOXO3 enhances radiation resistance in miR‐182 knockdown cells. In conclusion, our data suggested that miR‐182 might account for radioresistance in lung cancer and that miR‐182‐FOXO3 provides a novel radiosensitizing target. This article is protected by copyright. All rights reserved. - 'Clinical and Experimental Pharmacology and Physiology, Volume 0, Issue ja, -Not available-. '