Chronic inflammatory diseases of the lung are often life-threatening and are a leading cause of morbidity in our communities. MicroRNAs (miRs) are now recognized to play critical roles in a wide range of cellular functions, including the regulation of immunologic processes, which are often dysregulated in chronic respiratory diseases. These small noncoding RNA molecules regulate networks of genes by inhibiting translation through the targeting of one or multiple messenger RNA transcripts. This review highlights discoveries that identify important roles for miRs in the regulation of specific pathogenic features of a range of diseases. Furthermore, experimental evidence suggests that pharmacologic inhibition of miR function or delivery of mimics may have therapeutic potential. The review also therefore discusses the potential utility and limitations of therapeutically targeting these molecules and their downstream pathways.