Of the 44 currently accepted species ofPhytophthora, 18 have been reported in the Mediterranean area. The status of each is briefly reviewed. On citrus,P. citrophthoraandP. nicotianaevar.parasiticaare mainly responsible for foot rot and gummosis, and in additionP. hibernalis, P. syringae, P. cifricolaandP. cactorumfor brown rot of fruits. The incidence of these species is closely linked to their temperature requirements. The use of sour orange as a resistant rootstock has long provided satisfactory control of foot rot and gummosis, while chemical treatments are effective against brown rot. However, there are indications that, with changingcultural practices, the resistance of sour orange is less well expressed, and the species is incidentally also susceptible to citrus tristeza closterovirus. Alternative rootstocks are therefore being sought.