Introduction: Gefitinib along with other tyrosine kinase inhibitors contributed to better survival and lung adenocarcinoma treatment managing. As the aging of population is evident in our country, our point of interest was the effect of this therapy in geriatric patients. The Aim: The aim of study was to examine possible differences in survival between geriatric patients and patients under 65 years of age who have been treated with gefitinib and determine gefitinib side effects spectrum in this population.Material and Methods: Our study included 83 patients treated with gefitinib for lung adenocarcinoma in advanced stage: IIIb and IV, at the Institute for Pulmonary Diseases of Vojvodina in Sremska Kamenica in the period from 1 January 2011 to December 1, 2017. Results: Our results did not show a statistically significant difference in survival and spectrum of side effects in the geriatric population compared to chronologically younger patients. Median survival of geriatric patients was 11.1 months, and 23.9% werealive for two years of observation. The most commonly reported side effect of gefitinib in the examined geriatric population was diarrhea. Conclusion: Gefitinib therapy in carefully selected geriatric patients is favorable therapeutic choice for lung adenocarcinoma treatment with positive EGFR mutations, both in the survival parameters and in terms of the therapy adverse effects rate.