Piperlongumine, also known as piplartine, is an amide alkaloid of Piper longum L. (long piper), a medical plant known from Ayurvedic medicine. Although was discovered well over fifty years ago, its pharmacological properties have been uncovered in the past decade. In particular, piperlongumine has been most extensively studied as a potential anticancer agent. Piperlongumine has exhibited cytotoxicity against a broad spectrum of human cancer cell lines, as well as demonstrated antitumor activity in rodents. Piperlongumine has also been found to be a proapoptotic, anti-invasive, antiangiogenic agent and synergize with modern chemotherapeutic agents. Because of its clinical potential, several studies were undertaken to obtain piperlongumine analogues, which have exhibited more potent activity or more appropriate drug-like parameters. In this review, the synthesis of piperlongumine analogues and piperlongumine-based hybrid compounds, as well as their anticancer properties and the molecular basis for their activity are explored. General structure-activity relationship conclusions are drawn and directions for the future research are indicated.