Abstract In the Kimberley region of Western Australia, Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is only established at Broome. From 1998 to 2001 extensive fruit sampling was carried out at Broome during a trial investigating the eradication of medfly from the Kimberley using the sterile insect technique. Fruit was collected from 82 native and introduced plants growing in and surrounding the town of Broome and held for emergence of medfly. Eighteen plants, including the native tree Terminalia petiolaris, were found to be medfly hosts. On the basis of abundance, fruiting phenology and host suitability, eight species (kumquat Fortunella japonica, mango Magnifera indica, Barbados cherry Malpighia glabra, orange jessamine Murraya paniculata, guava Psidium guajava, Pacific almond Terminalia catapa, blackberry tree Terminalia petiolaris and yellow oleander Thevetia peruviana) were the most important hosts ensuring medfly survival and population growth. Despite medfly being reared from T. petiolaris, it is likely that medfly can only maintain populations in areas close to human habitation, and eradication from these areas would lead to eradication from the whole Kimberley region.