Background: Treatment for stage III non-small cell lung cancer (NSCLC) of unresectable disease mainly involves concurrent chemoradiation (CRT). Post-CRT consolidation treatment with durvalumab is a major therapeutic advance that provides survival benefit in this group of patients. However, the performance of this treatment strategy remains to be studied in a real-world setting. Methods: A total of 31 patients who had disease control post-CRT were included in the durvalumab early access program (EAP) as an intent-to-treat cohort and retrospectively reviewed for post-CRT progression-free survival (PFS) and time to metastatic disease or death (TMDD). The neutrophil-to-lymphocyte ratio (NLR) at the initiation of durvalumab was analyzed in 29 patients. Results: The median time from the completion of concurrent CRT to the initiation of durvalumb was 2.8 months. The objective response was 25.8% and the 12 month PFS and TMDD-free rate were 56.4% and 66.9%, respectively. The low NLR patients showed a significantly longer post-CRT PFS (not reach vs. 12.0 months [95% CI: 5.5-not estimable]; P = 0.040; the hazard ratio for disease progression or death, 0.23 [95% CI: 0.05-1.00]; P = 0.048) and the 12 month post-CRT PFS rate (82.5 vs. 42.6%). The post-CRT TMDD (not reach vs. 12.6 months, [95% CI: 10.8-not estimable]; P = 0.010; the hazard ratio for distant metastasis or death, 0.11 [95% CI: 0.01-0.88]; P = 0.037) and 12 month post-CRT TMDD-free rate (90.9 vs. 57.1%) were also significantly higher in the low NLR patients. Conclusions: Durvalumab consolidation treatment in real-world patients showed substantial efficacy and the correlation with the NLR level warrants further investigation.