<jats:p>The skin glands of the tree frog <jats:italic>Litoria chloris</jats:italic> contain a variety of peptides including four antibacterial peptides of the caerin 1 family. Two of these, caerins 1.6 and 1.7, are also present in the related species <jats:italic>Litoria xanthomera.</jats:italic> The other two peptides, caerins 1.8 and 1.9, are new. Their sequences are: GLFKVLGSVAKHLLPHVVPVIAEKL‐NH<jats:sub>2</jats:sub> [Caerin 1.8] and GLFGVLGSIAKHVLPHVVPVIAEKL‐NH<jats:sub>2</jats:sub> [Caerin 1.9]. Comparison of the skin peptide profiles of <jats:italic>L. chloris</jats:italic> and <jats:italic>L. xanthomera</jats:italic> confirms that these species are more closely related to each other than to any other species of the genus <jats:italic>Litoria</jats:italic> that we have studied. A comparison is made of the antibiotic activities of nine members of the caerin 1 family of peptides isolated from tree frogs of the genus <jats:italic>Litoria.</jats:italic>