MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded, tiny RNAs with 21-23 nucleotides that regulate several biological functions through binding to target mRNAs and modulating gene expression at post-transcriptional levels. Recent studies have described crucial roles for miRNAs in pathophysiology of numerous human cancers. They can act as an oncogene and promote cancer or as a tumor suppressor and alleviate the disease. Recently discovered microRNA-154 (miR-154) has been proposed to be involved in multiple physiological and pathological processes including cancer. With this aspect, aberrant expression of miR-154 has been demonstrated in variety of human malignancies, suggesting an important role for miR-154 in tumorigenesis. To be specific, it is considered as a tumor suppressor miRNA and exerts its beneficial effects by targeting several genes. This review systematically summarizes the recent advances done on the role of miR-154 in different cancers and discusses its potential prognostic, diagnostic and therapeutic values.