The importance of microRNAs (miRNA) in regulating immunity is becoming increasingly apparent as more miRNA targets are discovered and the molecular mechanisms underlying miRNA gene regulation becomes unraveled. miRNA are abundant and their expression is finely controlled in human epithelial cells at skin and mucosal sites. Recent studies indicate that miRNAs appear to regulate a diverse spectrum of epithelial cell functions including maintaining epithelial barrier integrity, refining intracellular signaling, and controlling epithelial immune responses to inflammatory stimuli and pathogens. Expanding our knowledge of the role of miRNA in epithelial immunoregulation as well as identifying miRNAs of pathogenetic significance will enhance our knowledge of epithelial immunobiology and immunopathology. This chapter will review recent advances in the identification and expression of epithelial cell miRNAs and highlight the functional significance of miRNA expression in immunoregulation of epithelial antimicrobial defense.