Cancer is an abnormal and uncontrolled proliferation of normal cells. The availability of safer anticancer drugs with exceptional selectivity for healthy cells and great efficacy against various cancer forms continues to be a significant obstacle. The piperazine moiety is used as the building block of several molecules and is reported to have the ability to inhibit the cell cycle (G1/S phase), inhibit angiogenesis, and interact with DNA. Piperazine also has a flexible binding feature that allows it to interact with a variety of biological targets, which makes it effective against cancers. As there is a continuous need to obtain an anticancer drug with improved efficacy and fewer side effects, the piperazine derivatives attract the attention of researchers. This review highlights the recently reported methods of synthesis of fused/substituted piperazines, structure–activity relationship, and interactions with targets/receptors as anticancer agents. Thus, the presented review will help medicinal chemists in designing anticancer molecules with piperazines.