MicroRNAs (miRNAs) are non-coding RNAs (ncRNAs) that can post-transcriptionally suppress targeted genes. Dysregulated miRNAs are associated with a variety of diseases. MiR-181a-5p is a conserved miRNA with the ability to regulate pathological processes, such as angiogenesis, inflammatory response and obesity. Numerous studies have demonstrated that miR-181a-5p exerts regulatory influence on cancer development and progression, acting as an oncomiR or tumor inhibitor in various cancer types by impacting multiple hallmarks of tumor. Generally, miR-181a-5p binds to target RNA sequences with partial complementarity, resulting in suppression of the targeted genes of miR-181a-5p. However, the precise role of miR-181a-5p in cancer remains incompletely understood. The present review aims to provide a comprehensive summary of recent research on miR-181a-5p, focusing on its involvement in different types of cancer and its potential as a diagnostic and prognostic biomarker, as well as its function in chemoresistance.