Recent advances in the field of RNA research have provided compelling evidence implicating long non-coding RNA molecules in many diverse and substantial biological processes that include transcriptional and post-transcriptional regulation of gene expression, genomic imprinting, modulation of protein activity and subcellular localization and cellular structural maintenance. While long non-coding RNAs have been most extensively studied in animal species, studies of long non-coding RNA in plants begin to emerge showing some conservation of mechanisms. This review aims to provide an overview of significant and recently identified long non-coding RNA-mediated mechanisms in both animal and plant species.