The invention relates to an antimicrobial peptide with heparin binding activity, being derived from endogenous mammalian proteins being substantially free from antimicrobial activity selected from the group consisting of laminin isoforms, complement factor C3, histidin rich glycoprotein and kininogen and having from 10 to 36 amino acid residues, wherein the antimicrobial peptide consists of at least four amino acid residues selected from the group consisting of K, R and H. The invention also relates to pharmaceutical compositions comprising said antimicrobial peptide and use of the antimicrobial peptide and/or antimicrobial/pharmaceutical composition.