Purpose <p>Non-small cell lung cancer (NSCLC) is characterized by a remarkably high mortality rate in clinical settings. This study aims to explore the mechanism of the miR-200a-5p/NFIA (nuclear factor I/A) axis in NSCLC and evaluate its potential as a clinical prognostic biomarker.</p> Methods <p>The study included 145 patients with NSCLC. The expression levels of miR-200a-5p and NFIA were quantified by quantitative reverse transcription polymerase chain reaction in tissues and cells. The prognostic value of miR-200a-5p was employed by Kaplan-Meier curves and Cox regression models. Cell proliferation, migration, and invasion were assessed using the cell counting kit-8 and Transwell assays. The potential target of miR-200a-5p were predicted by bioinformatics analysis. The interaction between miR-200a-5p and NFIA was validated by dual-luciferase assay.</p> Results <p>miR-200a-5p was upregulated in NSCLC tissues and cells, while NFIA was downregulated. High expression of miR-200a-5p was associated with a poor prognosis in NSCLC patients. Overexpression of miR-200a-5p promoted cell proliferation, migration, and invasion. NFIA was a target gene of miR-200a-5p. Overexpression of NFIA partially reversed the promotion effect of miR-200a-5p on cell proliferation, migration, and invasion.</p> Conclusion <p>Research findings indicate that miR-200a-5p is overexpressed in NSCLC, and the high expression of miR-200a-5p is an independent adverse prognostic factor for NSCLC patients. miR-200a-5p promotes cell proliferation, migration and invasion by targeting and inhibiting NFIA. Although these findings require further validation in multicenter cohorts and in vivo models, miR-200a-5p shows potential as an independent prognostic biomarker and a therapeutic target in NSCLC.</p>