Anticancer peptides (ACPs) are naturally occurring molecules that preferentially kill cancer cells. Although ACPs represent attractive new drugs, their clinical utility is limited by severe side-effects. Here, we exploit the interactions of ACPs with cancer cell membranes to prepare a new class of membrane-mimetic ACP nanoparticles, referred to as a lipopeptisome (LP). We show that LPs potently destroy cancer cells without significant damage to healthy tissues, thus transforming previously toxic drugs into clinically viable therapies.