To investigate the clinical value of EGFR mutation testing in peripheral blood of patients with non-small cell lung cancer.This was a retrospective study. A total of 89 patients with non-small cell lung cancer (NSCLC) admitted to Affiliated Hospital of Hebei University between June 2019 and May 2023 were selected, and divided into the wild-type group and the mutant group according to the results of EGFR mutation testing in peripheral blood. Clinic pathological data of patients were collected and compared between the two groups, the correlation between EGFR mutation and the prognosis was analyzed.No statistically significant difference in the mutation rate of EGFR gene was observed between peripheral blood ctDNA and tumor tissue (p=0.879). EGFR mutation in peripheral blood ctDNA was not significantly correlated with sex, age, ethnicity and ECOG score (p>0.05). The EGFR mutation rate was increased in patients with adenocarcinoma compared with that in patient with squamous carcinoma, and in non-smoking patients compared with that in smoking patients, and the differences were statistically significant (p<0.05). The 1-, 2-, and 3-year disease-free survival (DFS) rates were significantly increased in the mutant group compared with those in the wild-type group, respectively (p<0.05).EGFR mutation in peripheral blood and tumor tissues is highly consistent in NSCLC patients. The EGFR mutation rate is higher in adenocarcinoma and non-smoking patients, and the prognosis is better in patients with EGFR mutations.Copyright: © Pakistan Journal of Medical Sciences.