Recently, microRNAs (miRNAs) including miR-34 family have been found to play a critical role in tumorigenesis through regulating the expression of its target genes, which are involved in many cellular processes such as cell proliferation, survival, apoptosis, migration, invasion and angiogenesis. Thus, this review described the role of miR-34 family and how its deregulation is involved in the development and progression of human malignances. Moreover, we described the potential role of miR-34 as a novel biomarker for tumor diagnosis. Furthermore, we summarized that miR-34 family could be up-regulated by natural compounds in human cancers. Therefore, targeting miR-34 family could be a novel strategy for achieving better treatment outcome of cancer patients in the future.