Dysregulation in the expression of miRNAs has been observed in various human cancers, including lung cancer. Recent studies have identified the role of a number of miRNAs in regulating key cellular processes and signaling pathways involved in lung tumourigenesis, including cell proliferation, differentiation, angiogenesis, apoptosis, invasion and metastasis. Due to their variable behavior and regulatory role in various nodal junctions in cellular pathways, miRNAs have also been used as potential therapeutic targets and clinical biomarkers in lung cancer. In this non-systematic review, we briefly focus on biogenesis and function of cytoplasmic miRNA and the role of methylation in the regulation of miRNA biogenesis in non-small cell lung cancer (NSCLC). Further, we elaborate the role of differentially expressed miRNAs and their regulatory role on various signaling pathways, cell cycle, and apoptosis in NSCLC.