The habitat and feeding behaviour of giraffe in the Willem Pretorius Game Reserve, Orange Free State, are described. Acacia karroo, the single most important component, together with Asparagus laricinus, Rhus undulata and Ziziphus mucronata, comprises almost 90% of the giraffe's diet. During the wet season deciduous plants of the savanna flats are preferred, but in the dry season the animals concentrate on evergreen plants in the more densely vegetated kopjies. Seasonal variation with respect to the number of plant species utilized, the intake of woody plant material and the frequency of aberrant behaviour patterns associated with feeding, also occur. Seasonal peaks in reproduction and daily rest periods are apparently influenced by energy requirements and the availability of preferred food species. The effect of browsing on the vegetation as well as other considerations, necessitate limitation of the increase of the giraffe population in the game reserve.