Background Concurrent chemoradiotherapy (CCRT) is an optimal recommended treatment for stage III non‐small cell lung cancer (NSCLC). Herein, we aimed to investigate the efficacy and safety of oral vinorelbine plus cisplatin with concomitant radiotherapy for stage III NSCLC. Methods This prospective, open‐label, single‐arm, observational cohort study was performed between January 2010 and September 2016. Patients were treated with two cycles of chemotherapy with 60 mg/m2 intravenous cisplatin on day 1 and 50 mg/m2 oral vinorelbine on days 1, 8, and 15; radiotherapy was administered concurrently from day 1 when chemotherapy was initiated. A total dose of 66–70 Gy radiotherapy was delivered in daily fractions of 2 Gy for 6.5–7 consecutive weeks. The tumor response was assessed after completing concomitant treatment. Results A total of 58 patients were enrolled and analyzed; 31 patients had stage IIIA NSCLC and 27 had stage IIIB NSCLC. After induction CCRT, 31 patients achieved an objective response (complete response in one and partial response in 30; the response rate was 53.4%). The median progression‐free survival was 6.73 months (95% confidence interval [CI], 5.42–7.91), duration of response was 12.30 months (95% CI, 5.59–19.01), and overall survival was 24.83 months (95% CI, 19.26–30.21). No treatment‐related mortality was observed, and neutropenia was the most common grade 3 and 4 treatment‐related toxicity (11 patients; 18.9%). Conclusions CCRT with the weekly regimen of oral vinorelbine plus triweekly cisplatin was effective and safe for stage III NSCLC.