We analysed the crop contents of 94 Pyrenean Grey Partridges Perdix perdix hispaniensis collected in the eastern Pyrenees from 1980 to 1996. Birds were shot by hunters in September-November over a large range of altitudes (1 000-2 400 m). The various food items were classified into six categories (grasses, forbs, seeds, berries, tubers-bulbs and animal prey), dried in an oven and weighed. Preparations of epidermal cells were made to identify grasses and forbs. Vegetable matter accounted for 79 % of dry weight. Grasses and forbs, in spite of high frequencies of occurrence (respectively 72 % and 84 %), contributed least to total dry weight. Seeds and animal prey, mainly Orthoptera, were the most important autumn foods, comprising respectively 30 % and 21 % of the total dry weight. There was neither age-related nor altitude-related difference in the foods eaten, but the contribution of green matter was higher in late autumn (> 20.X) than in early autumn. Seventy five plant species were identified. The identification of epidermal cells of grasses by microscopic analysis showed a high frequency of the following three species : Poa alpina, Festuca rubra and F. ovina. At least 29 % (20/70) of vegetable species eaten by partridges were characteristic of pastures subjected to a high grazing pressure. In terms of habitat selection, these features suggest that in late autumn Grey Partridges sought mainly areas intensively grazed by cattle. In the mountainous habitat of the Grey Partridge, like shrublands of broom (Cytisus purgans), the floristic diversity is generally poor. Thus, grazing could improve both the diversity of flora and the level of nitrogen content of vegetable foods.