Antimicrobial peptides are part of the plant defense system. They are present in all plant organs and in a wide range of plant species and their antimicrobial effects have been proven against phytopathogens as well as human pathogens, viruses, bacteria, fungi, and protozoa , parasites and cancer cell lines. Thus these peptides are promising antibiotic compounds with important applications in pharmaceutical biotechnology. Antimicrobial peptides of plants are grouped in several families based on general characteristics such as positive charge and presence of disulfide bands. Most naturally antimicrobial peptides are between 10 and 50 amino acids long, range in size from 2 to 9 kDa, positively charged, contain highly hydrophobic amino acids, and often have helical structures. The set of antimicrobial peptides synthesized by plants is homologous to the amino acid sequence of defensins, thionins, lipid transfer proteins, cyclotides, snakins, and hevein-like proteins. Antimicrobial peptides of plants have a high potential in health and agricultural care as a natural antibiotic and are an alternative to chemicals to protect humans, plants or animals from disease.