SUMMARYPeronophythora litchiiwas isolated again from diseased litchi fruits and its morphology reinvestigated. Its sex organs and its ability to grow on artificial media are characteristic of the Pythiaceae. However, the branched, determinate sporangiophores of this fungus resemble those of the Peronosporaceae. The name of the speciesPeronophythora litchiiis validated and a new family, Peronophythoraceae, is proposed to accommodate the fungus. A key to the families of Peronosporales is presented.