Patients with N3 non-small cell lung cancer (NSCLC) have unresectable tumors. Although significant progress has been made in the past decades for such tumors, the average median survival time remains at 10 months. Equally dismal long-term survival rates were reported with the average 5-year-suvival rate at 9%. Here, we report on a case of a patient with locally advanced disease that was treated with conversion therapy using targeted anti-PD-1 immunotherapy with platinum-based chemotherapy. Following this therapeutic regimen, the tumor showed a reversion to pN0 from pN3 and the patient showed a progression free survival time of at least 33 months.