microRNAs (miRNAs) are small noncoding RNAs able to suppress gene expression by targeting messenger RNAs for translational repression or, at lesser extent, degradation. miRNAs are widely expressed in tissues and organs and play fundamental roles in controlling cell proliferation, apoptosis, differentiation, cell migration, autophagy and metabolism. Uncontrolled expression of miRNAs has been associated with cancer progression, and miRNA up- or down-regulation has been linked to oncogenic and tumor-suppressive roles in cancers such as breast cancer, colorectal cancer, lung cancer, gastric cancer and glioblastoma. Altered expression of the miRNA mir-25 has been reported in many human malignant tumors, participating in various cellular processes accordingly with its broad range of potential mRNAs target. In the present review, we briefly discuss the mechanisms underlying miR-25-mediated tumorigenesis in six different human cancers and its possible future as a potential diagnostic and prognostic parameter as well as therapeutic target in clinical applications.