microRNAs are small noncoding RNAs that regulate protein-coding genes via posttranscriptional repression. Most protein-coding genes are subjected to microRNA-mediated regulation, making the potential effect of these small molecules on regulatory networks enormous. Recent research has implicated miRNAs in the regulation of innate and adaptive immune responses as well as inflammatory networks in various cell and tissue types. In this review, we summarize the current knowledge about miRNAs in immunity and inflammation, focusing on the recent results on miRNAs involved in the regulation of immune responses and inflammatory diseases.