Cape Parrots have the most restricted trophic niche of any Poicephalus species studied thus far. Their diet is specialised to yellowwood fruits throughout the year, including all three tree species distributed within their historical range. Due to the variable fruiting phenology of yellowwood species, Cape Parrots are food nomadics meaning they move between forest patches occasionally making long feeding forays of up to 100km away at coastal forests (Skead 1964; Skead 1971). 

In their natural habitat, Cape Parrots are known to also feed on Cape Chestnut (Calodendrum capense), Red stinkwood (Prunus africana), Cape Beech (Rapaneae melanophloes), Highveld Protea (Protea caffra), Cat-thorn (Scutia myrtina), Sneezewood (Ptaeroxylon obliquum), Pittosporum (Pittosporum viridiflorum), Ironwood (Olea capensis), White Stinkwood (Celtis africana), White Pear (Apodytes dimidiata) and the exotic, all-pervasive Black Wattle (Acacia mearnsi).

In recent years, there have been an increasing number of reports of Cape Parrots feeding on exotic tree species in residential and rural gardens (e.g., Syringa (Melia azedarach)) and on fruit and nuts in orchards (e.g., pecan farms throughout their range).