MicroRNAs (miRNAs), as a class of small, well-conserved, non-coding RNA molecules, hold the capacity to post-transcriptionally suppress the expression of over 50% protein-coding genes. Emerging and accumulating evidence suggests that miRNAs function as the master regulators of multiple pathophysiological processes, and play important roles in diverse human diseases, especially in tumorigenesis and progression. MiR-106b-5p, a member of miR-106b seed family, has been demonstrated to be aberrantly expressed in human solid malignancies, and to play paradoxically opposing functions as an oncomiR or a tumor suppressor in tumor development. In addition, it has been recently reported to be a promising biomarker for prognostic evaluation for cancer patients. In the present review, we provided an overview to summarize the present findings of miR-106b-5p in cancer research fields, thereby establishing comprehensive understanding of its diverse functions and clinical implications in human cancers.