FAM72A-D promote the self-renewal of neural progenitor cells. There is accumulating evidence that FAM72 promotes tumorigenicity. However, its effects in lung adenocarcinoma (LUAD) have not been determined. Thus, we evaluated the prognostic value of in LUAD using bioinformatics approaches. In particular, we evaluated the relationship between FAM72 and LUAD using a wide range of databases and analysis tools, including TCGA, GEO, GEPIA, Metascape, cBioPortal, and MethSurv. Compared with its expression in normal lung tissues, FAM72 expression was significantly increased in LUAD tissues. A univariate Cox analysis showed that high FAM72 expression levels were correlated with a poor OS in LUAD. Additionally, FAM72 expression was independently associated with OS through a multivariate Cox analysis. GO and GSEA revealed enrichment in mitotic nuclear division and cell cycle. Moreover, high FAM72 expression was associated with poor survival. An analysis of immune infiltration showed that FAM72 is correlated with immune cell infiltration. Finally, we found that the methylation level was associated with prognosis in patients with LUAD. In summary, these results indicate that FAM72 is a potential molecular marker for poor prognosis in LUAD and provide additional insight for the development of therapies and prognostic markers.