Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) represent novel effective agents approved for the treatment of patients with advanced-stage NSCLC. KRAS mutations have been reported as a negative prognostic and predictive factor in patients with NSCLC treated with EGFR-TKIs. Several studies have recently shown that statins can block tumour cell growth, invasion and metastatic potential. We analysed clinical data of 67 patients with locally advanced (IIIB) or metastatic stage (IV) NSCLC harbouring Kirsten rat sarcoma viral oncogene (KRAS) mutation treated with erlotinib or gefitinib. Twelve patients were treated with combination of EGFR-TKI and statin and 55 patients were treated with EGFR-TKI alone. Comparison of patients' survival (progression-free survival (PFS) and overall survival (OS)) according to the treatment used was performed using the Gehan-Wilcoxon test. The median of PFS and OS for patients treated with EGFR-TKI alone was 1.0 and 5.4 months compared to 2.0 and 14.0 months for patients treated with combination of EGFR-TKI and statin (p = 0.025, p = 0.130). In conclusion, the study results suggest significant improvement of PFS for patients treated with combination of statin and EGFR-TKI, and the difference in OS was not significant.