Abstract: MicroRNAs (miRNA) are a class of small non-coding RNA molecules that are rich in content and are highly conserved. miRNA can regulate vital biological processes, including cell division, differentiation, and cell apoptosis. Their expression is dysregulated in many diseases. miRNA are essential in the initiation and development of various cancers. Recent miRNA studies have gradually moved from basic molecular studies of cancer onto areas of clinical application. The use of miRNA as biomarkers for cancer diagnosis and target molecules for cancer treatment is increasingly being identified. This review summarizes the potential applications of miRNA as biomarkers for diagnosis and prognosis of gastric cancer, drug response, and susceptibility prediction.