Prostate cancer-associated transcript 1 (PCAT-1) is a newly identified long non-coding RNA comprising two exons, located in the Chr8q24 gene desert approximately 725 kb upstream of the MYC oncogene. PCAT-1 is dysregulated and acts as an oncogene in different types of cancers and has been implicated in several processes correlated with carcinogenesis, such as cell proliferation, invasion, metastasis, apoptosis, cell cycle, chemoresistance, and homologous recombination. The mechanisms underlying the effects of PCAT-1 are complex and involve multiple factors and signaling pathways. In this paper, we systematically review the multiple pathological functions of PCAT-1 in diverse malignancies to elucidate its potential molecular mechanisms and to provide new directions for future research.