Objective To clarify the expression and clinical significance of ARHGAP11A in lung adenocarcinoma. Methods The expression of ARHGAP11A in lung adenocarcinoma and normal tissue was obtained and analyzed by searching online databases such as Oncomine, and bioinformatic analysis was carried out on the relevant clinicopathological parameters and survival data of lung cancer patients. PrognoScan prognostic analysis database was used to analyze the relationship between ARHGAP11A gene expression and prognosis of lung adenocarcinoma. STRING database was used to construct ARHGAP11A and its function-related gene network. Results Compared with normal tissue, ARHGAP11A was highly expressed in lung adenocarcinoma, and the later the clinical stage and the worse the differentiation, the higher the expression of ARHGAP11A and the worse the prognosis. Conclusion ARHGAP11A is highly expressed in lung adenocarcinoma and is related to poor prognosis of lung adenocarcinoma.