The development of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) changed dramatically the history of non-small cell lung cancer (NSCLC) harboring EGFR sensitive mutations. Several randomized prospective trials confirmed the superiority of these target agents about survival and response rate when comparing with platinum-based chemotherapy. Knowledge about EGFR mutations increased gradually during the development of target agents and different clinical trials. EGFR mutations cannot be considered all equal, but different entities should be considered in our clinical practice: exon 19 deletions, exon 21 mutation (L858R) and uncommon mutation (exon 20, exon 18 and double mutation). Nowadays, we dispose of three different EGFR TKIs (afatinib, erlotinib and gefitinib) approved for the treatment for first-line treatment of patients di NSCLC carrying EGFR, that was compared only by indirect analysis, producing data not always clear and convincing. This research highlight is an overview of data about EGFR TKIs in first-line setting, focusing on differences about exon 19 deletions and L585R mutation in patients treated with different TKIs. In addition, we report the preliminary results of the first head-to-head randomized clinical trial between two different EGFR TKIs, the LUX-Lung 7 (LL7) that compared afatinib and gefitinib showing interesting results.