ObjectiveTo identify causal effects and potential mechanisms of oxidative stress (OS)-related genes in lung cancer. MethodsOS-related genes were extracted from the GeneCards database. Integration analysis of genome-wide association study (GWAS) data for lung cancer with gene expression and DNA methylation quantitative trait locus (QTL), including eQTL and mQTL in blood was performed using the summary data-based Mendelian randomization (SMR) approach to determine the causal relationship between OS-related genes and lung cancer risk. Colocalization analysis of OS-related gene QTL and lung cancer risk locus was performed to gain insight into the potential regulatory mechanisms of lung cancer risk. ResultsA total of 1 188 OS-related genes were obtained from the GeneCards database. A potential causal relationship between OS-related genes and lung cancer was identified by SMR analysis. AGER expression level [OR=1.944, 95%CI (1.431, 2.640), P<0.001], and ATF6B expression level [OR=1.508, 95%CI (1.287, 1.767), P<0.001] were associated with lung cancer risk. Meanwhile, ATF6B methylation level was also associated with lung cancer risk. ConclusionOS-related genes are associated with lung cancer, which may be a potential target of anti-cancer drugs.