Objective To explore the value of CT perfusion imaging (CTP) in evaluating the curative effect of radiotherapy for non-small cell lung cancer (NSCLC). Methods Ninety-six patients with pathologically confirmed NSCLC who underwent radiotherapy were selected. CTP was performed before and after radiotherapy to obtain CTP parameters blood volume (BV) and blood flow (BF) in the tumor area. The changes of BV and BF before and after radiotherapy were compared. The ROC curve was used to analyze the efficiencies of the reduction rate of BV and the reduction rate of BF for evaluation of the curative effect of radiotherapy. Results Among the 90 patients, there was no patient with CR, 46 patients with PR, 37 patients with SD and 7 patients with PD after radiotherapy, and the remission rate was 51.11% (46/90). The BV and BF were significantly decreased after radiotherapy (P<0.05). Compared with the non-remission group, the reduction rates of BV and BF were significantly higher in the remission group after radiotherapy (P<0.05). ROC curve analysis showed that the efficiencies of reduction rates of BV and BF (43.20% and 16.50%) were the best for evaluation of the curative effect of radiotherapy. The areas under ROC curve were 0.839 and 0.811. The corresponding sensitivities, specificities and accuracy rates were 82.61%, 88.64%, 85.56% and 80.43%, 84.09% and 82.22%, respectively. Conclusion CTP parameters, namely the reduction rates of BV and BF can be used as evaluation indexes for the curative effect of radiotherapy for NSCLC.