With the development of advanced imaging and radiation technologies, radiotherapy has been employed as the principal treatment approach for nasopharyngeal carcinoma (NPC). So far, a number of patients still suffer from the failure of this treatment due to the acquired radioresistance, but the underlying mechanisms are still poorly defined. In this study, we found that Twist1, participating in a variety of cell biological process, was associated with the malignancy of NPC and could induce NPC radioresistance in vitro and in vivo. Mechanically, Twist1 could promote the accumulation of DNA damage repair and inhibit the apoptosis of NPC cells. Therefore, our study not only elucidates the significant role of Twist1 in radioresistance of NPC, but also highlights Twist1 as a potential therapeutic target for NPC.