A novel class of cationic peptides having antimicrobial activity is disclosed. These peptides can be encompassed by the formulas: TABLE-US-00001 X.sub.1X.sub.1PX.sub.2X.sub.3X.sub.2P(X.sub.2X.sub.2P).sub.nX.sub.2X.sub.3- (X.sub.5).sub.0; (SEQ ID NO:23) X.sub.1X.sub.1PX.sub.2X.sub.3X.sub.4(X.sub.5).sub.rPX.sub.2X.sub.3X.sub.3;- (SEQ ID NO:24) X.sub.1X.sub.1X.sub.3(PW).sub.uX.sub.3X.sub.2X.sub.5X.sub.2X.sub.2X.sub.5X- .sub.2(X.sub.5).sub.0; and (SEQ ID NO:25) X.sub.1X.sub.1X.sub.3X.sub.3X.sub.2P(X.sub.2X.sub.2P).sub.nX.sub.2(X.sub.5- ).sub.m; (SEQ ID NO:26) wherein: m is 1 to 5; n is 1 or 2; o is 2 to 5; r is 0 to 8; u is 0 or 1; X.sub.1 is Isoleucine, Leucine, Valine, Phenylalanine, Tyrosine, Tryptophan or Methionine; X.sub.2 represents Tryptophan or Phenylalanine X.sub.3 represents Arginine or Lysine; X.sub.4 represents Tryptophan or Lysine; and X.sub.5 represents Phenylalanine, Tryptophan, Arginine, Lysine, or Proline. The invention also provides a method of producing a cationic peptide variant having antimicrobial activity.