Diabetes Mellitus (DM), often simply referred to as diabetes, has developed into a major health concern affecting more than 200 million people worldwide with approximately 4 million deaths per year attributed to the presence of the disease. Diabetes mellitus is categorized as Type 1 and Type 2, where Type 1 diabetes represents a lack of insulin production, and Type 2 diabetes is characterized by a relative lack of insulin receptor (i.e., decreased sensitivity to the effect of insulin) and cased by a complex interplay between genetic factors and environmental factors. Up to date, various studies on the pathology and mechanism in terms of genetic experiments have been conducted and approximately hundreds of genes were reported as diabetes mellitus associated genes. At this point, to support studies on the cause and mechanism of diabetes mellitus, an efficient database system to provide genetic variants related to diabetes mellitus is needed. DMBase is an integrated web-based genetic information resource for diabetes mellitus designed to service genomic variants, genes, and secondary information derived for diabetes mellitus genetics researchers. The current version of DMBase documents 754 genes with 3056 genetic variants and 66 pathways. It provides many effective search interfaces for retrieving diabetes mellitus and genetic information. A web interface for the DMBase is freely available at http://sysbio.kribb.re.kr/dmBase.