MicroRNAs (miRNAs) are a recently discovered category of small RNA molecules that regulate gene expression at the post-transcriptional level. Accumulating evidence indicated that miRNAs are aberrantly expressed in a variety of human cancers and crucial to tumorigenesis. We herein provide a brief review of miRNA biogenesis, function, deregulation and their possible role as oncogenes or tumor suppressors in the pathogenesis of gastric cancer. The role of miRNAs in the carcinogenic effect of Helicobacter pylori infection was also discussed. Finally, we comment on the potential role of miRNAs in improving the current management of gastric cancer.