This study aimed to analyze the expression of 8-oxoguanine DNA glycosylase (OGG1) in patients with hepatocellular carcinoma (HCC) and its effect on prognosis by bioinformatics techniques and to determine its possible carcinogenic mechanism through data mining.The difference in OGG1 expression between healthy people and HCC patients was searched and analyzed by TCGA and GEO databases, and the effect of OGG1 on prognosis was judged by survival analysis. Meanwhile, the possible molecular mechanism of OGG1 in the tumorigenesis and development of HCC was explored by GO analysis, KEGG analysis, immune infiltration analysis, protein-protein interaction network, promoter methylation analysis, and so forth. Quantitative polymerase chain reaction (qPCR) was used to examine the gene expression in 36 pairs of HCC tissues and adjacent tissues.The expression of OGG1 in HCC patients was higher than that in healthy people, and the overexpression of OGG1 might stimulate cell proliferation by increasing the activity of cell cycle-related proteins.The alteration of OGG1 was significantly correlated with the tumorigenesis and development of HCC. OGG1 is expected to be a new biomarker for evaluating the prognosis of HCC and a new target for the treatment of HCC.© 2022 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.