The minichromosome maintenance (MCM) gene family plays an essential role in DNA replication and cell cycle progression. However, MCM gene expression has not been well‑studied in lung adenocarcinoma (LUAD). In the present study, the expression, prognostic value and functions of MCMs in LUAD were investigated using several databases and bioinformatic tools, including Oncomine, GEPIA, cBioPortal, CancerSEA and Kaplan‑Meier plotter. It was demonstrated that the mRNA expression of MCM2, MCM4 and MCM10 were significantly increased in patients with LUAD. High mRNA expression of MCM2‑5, MCM8 and MCM10 were associated with poor overall survival and progression‑free survival. High MCM4 expression was associated with adverse post‑progression survival. In addition, the Human Protein Atlas database showed that MCM protein expression was consistent with the mRNA expression. These results demonstrate that MCM2, MCM4 and MCM10 are potential prognostic markers and therapeutic targets for LUAD.