Being sessile in nature, plants have evolved sophisticated gene regulatory mechanisms to drive their growth and development as well as cope with environmental cues. This may involve expression and silencing of specific genes. A large family of non-coding RNAs (ncRNAs) are involved in silencing the gene expression at both transcriptional and post- transcriptional levels. The role of small ncRNAs such as microRNAs and small interfering RNAs has been extensively studied in response to various stresses. The increasing insights on role of lncRNA and their functional validations have unveiled their potential as genetic regulators in plants. In this chapter, we present the detailed biology, classification, mode of action and gene regulatory function of lncRNA in plant growth, development and biotic and abiotic stress responses. We also present an update on the methods and databases for lncRNA identification and characterization in plants.