The whole human genome sequence analysis has identified a large proportion of transcripts that lack protein-encoding function known as noncoding RNAs (ncRNAs). Long ncRNAs (lncRNAs) are transcripts consisting of more than 200 nucleotides. LncRNAs are identified as key regulators for diverse biological processes, including gene expressions, epigenetic modulations, transcriptional and translational regulation. LncRNAs-based mechanisms control gene activation, and cellular processes, while the dysregulated lncRNAs are associated with various disorders, including cancer. Moreover, lncRNAs have potential in diagnosis and prognosis of cancer. Several lncRNAs contribute to cancer development, metastatic cascade, and their molecular regulations in cancer development. The aberrant expression of lncRNAs regulates tumorigenesis, proliferation, metastasis, cancer stage, tumor size, and overall survival rates. Several lncRNAs are highly expressed or downregulated in several human tumors, behaving as oncogenes or tumor suppressors, respectively. The unique expression level of oncogenic lncRNAs provides a possibility to utilize them as a promising predictive biomarker of cancer.