Although cancer and neurodegenerative disease are two distinct pathological disorders, emerging evidence indicates that these two types of disease share common mechanisms of genetic and molecular abnormalities. Recent studies show that individual microRNAs (miRNAs) could be involved in the pathology of both diseases, indicating that the mechanisms of these two seemingly dichotomous diseases converge in the dysregulation of gene expression at the post-transcriptional level. Given the increasing evidence showing that miRNA-based therapeutic strategies that modulate the activity of one or more miRNAs are potentially effective for a wide range of pathological conditions, the involvement of miRNAs in the common pathways of leading both diseases suggests a bright future for developing common therapeutic approaches for both diseases. Moreover, the miRNAs that are dysregulated in both diseases may hold promise as uniquely informative diagnostic markers. Here, we review recent studies on the miRNAs that have been implicated in both cancer and neurodegenerative diseases.