Prostate cancer (PCa) is the second most common cause of cancer-related deaths in men. Despite advances in the characterization of genomic and epigenetic aberrations contributing to PCa, the etiology of PCa is still far from being understood. Research over the past decade demonstrated the role of long non-coding RNAs (lncRNAs) in deregulation of target genes mainly through epigenetic mechanisms. In PCa, evidence accumulated that hundreds of lncRNAs are dysregulated. Functional analyses revealed their contribution to prostate carcinogenesis by targeting relevant pathways and gene regulation mechanisms including PTEN/AKT and androgen receptor signaling as well as chromatin remodeling complexes. Here we summarize our current knowledge on the roles of lncRNAs in PCa and their potential use as biomarkers for aggressive PCa and as novel therapeutic targets.