Recently, transcriptome-wide sequencing data have revealed the pervasiveness of intergenic long noncoding RNA (lncRNA) transcription. Subsets of lncRNAs have been demonstrated to crosstalk with and post-transcriptionally regulate mRNAs in a microRNA (miRNA)-dependent manner. Referred to as long noncoding competitive endogenous RNAs (lnceRNAs), these transcripts can contribute to diverse aspects of organismal and cellular biology, likely by providing a hitherto unrecognized layer of gene expression regulation. Here, we discuss the biological relevance of post-transcriptional regulation by lnceRNAs, provide insights on recent advances in the understanding of lnceRNA regulatory networks, and speculate on molecular factors that facilitate miRNA-dependent crosstalk between lnceRNAs and other transcripts.