Despite advances in the treatment of cancer, lung cancer still takes the first place in the structure of mortality from malignant neoplasms. Non-small cell lung cancer (NSCLC) is about 85% of all cases of lung cancer. The standard treatment of early NSCLC is surgical approach. Because of the large proportion of patients who continue to suffer from local recurrence after radical surgery and adjuvant chemotherapy it is necessary to reconsider the role of postoperative radiation therapy (PORT) in NSCLC patients. The results of the meta-analysis of using of PORT, published in 1998, were disappointing. Adjuvant radiotherapy for pN0 pN1 increased the risk of death by 21%, reducing the 2-year overall survival by 7%. At stage III and pN2 patients results were controversial: PORT slightly improved local control, but had no effect on overall survival. Along with criticism of this meta-analysis, the literature provides evidence from randomized studies confirming benefits of the using of PORT. In this review article potential misconceptions about the "dangers" of PORT as well as critical issues for determining the indications for PORT in NSCLC are considered. Despite advances in the treatment of lung cancer it still takes first place in the structure of mortality from cancer in many countries, including Russian Federation. Non-small cell lung cancer (NSCLC) is about 85% of all cases of lung cancer. Patients with I, II and IIIA stage of NSCLC are considered potentially resectable with 5-year survival after radical surgery ~ 60-90%, 30- 70% and 10-30%, respectively. The standard treatment of early NSCLC is surgical approach. Adjuvant therapy is not recommended for patients with stage I of NSCLC after R0-resection in accordance with the guidelines NCCNV.3.2014. However, the 5-year survival rate for patients with stage I of NSCLC according to different studies ranges from 50% to 90% with relapse within 5 years after surgery, which stimulates the researches for an effective adjuvant therapy for the last few decades.