Bacterial resistance to conventional antibiotics is an ever increasing problem in the treatment of infectious disease. The basic problem is that conventional antibiotics, which generally operate by inhibiting some bacterial enzyme(s), can be rendered ineffective by overuse, natural selection and induced bacterial mutations. A novel class of antibiotics that functions by disrupting the superstructure of bacterial membranes rather than by inhibiting any specific enzyme has presented itself as the future for antibiotics. Most of these bactericidal agents are peptides of peptide-based molecules that have been either isolated from natural sources or synthetically designed. Here we review recent research into the development of peptides as bacterial membrane-disintegrating agents.