A vegetation assessment and an investigation of feral goat (Capra hircus) diet in Isolated Hill Scenic Reserve, Southern Marlborough, were completed to provide Department of Conservation managers with exact information on the impacts of feral goats in the reserve. Regeneration of two species; Griselinia littoralis and Melicytus rami.florus was found to be rare except in the three exclosure plots established in the reserve in 1985. Woody sapling numbers ha-1 were also found to be lower outside of the exclosure plots. However, unpalatable woody species were found to be increasing in number outside exclosures, in particular Coprosma crassifolia and C.rhamnoides. Assessment of impacts were only possible for five of the 13 vegetation types present in the reserve due to placement of plots in 1985. Feral goat rumens were found to contain between 2-10 plant taxa. Diet was dominated by three taxa; Griselinia littora/is (38.6%), monocotyledon species (19.3%), and Melicytus ramiflorus (12.0%). Sex, age and season were found to be significant determinants of consumption for three principal food groups. Preference ratings were calculated for each plant species eaten using availability data from the vegetation assessment and percentage of diet from the rumen analysis. Five plant taxa had positive preference ratings - G. littoralis, (0.73); M ramiflorus, (0.66); Cordyline australis, (0.31); grasses and sedges, (0.24); and Sophora microphylla, (0.04) - suggesting that these groups are being removed from the reserve. After consideration of these results (and consideration of the effects of adventive weed species and other vertebrate pests present in the reserve) a recommendation has been made to base monitoring and auditing of future feral goat control on the regeneration success of G. littoralis and M. ramiflorus. A recommendation to increase the number of exclosure and non-exclosure plots in the reserve, has also been made.