Human type 1 diabetes (T1D) is a chronic autoimmune disorder with complex genetic inheritance. To date, more than 19 insulin-dependent diabetes mellitus (IDDM) susceptibility loci have been mapped to specific chromosome regions in the human. MicroRNAs (miRNAs) are a recently discovered class of evolutionarily conserved small noncoding RNAs that negatively regulate the expression of protein-coding genes without affecting mRNA levels. There are a growing number of reports that miRNAs link to the regulation of different biological pathways associated with human diseases. However, the potential role of miRNAs in human T1D is still unknown. To investigate the possible involvements of miRNAs in human T1D on a genome-wide basis, we have mapped 530 miRNAs and compared their locations to the current IDDM loci. We found that at least 27 miRNAs are located in 9 human IDDM loci. More interestingly, some of them potentially target autoimmune- and beta-cell-related genes. Our data represent a genome-wide search for a potential correlation between the genomic position of miRNAs and specific IDDM loci, indicating that miRNAs may be susceptibility candidates or biomarkers for human T1D.