Adjuvant radiotherapy following radical surgery in NSCLC has long been a matter of debate. The pros and cons have all been discussed thoroughly and the data existing due to their partial outdated nature in respect of the diagnostic and therapeutic maneuvers used make it difficult to rely on them. Based on the existing level of evidence from randomized studies, the decision to irradiate a NSCLC patient postoperatively does not seem to be prudent, as several meta-analyses in fact have rather shown a detrimental effect than any benefit. As the majority of the randomized trials that are the bases of the meta-analyses are neither of good quality nor include those patients that are nowadays regarded as those for whom adjuvant irradiation should be discussed, other sources of information are of relevance. Subanalyses of randomized phase III trials and recently published SEER data are indicative that there is a benefit from adjuvant irradiation not only in terms of freedom from local failure but of overall survival as well. Notably, this is not at the expense of unacceptably high rates of long-term side effects.