By micro-histological analysis of plant remains in faecal pellets, we studied the diet of red deer Cervus elaphus during a summer season in the subalpine zone of the Swiss National Park in the eastern Swiss Alps. Hitherto, very little quantitative information on the diet of Alpine red deer populations has been published. Faecal species composition was found to conform to the general pattern known from elsewhere: it was dominated by graminoids with dwarf shrubs (mainly Erica camea) as a strong secondary component and forbs and coniferous browse in minor proportions. Practically all pellet samples contained food obtained both from pastures and forests, irrespectively of where the pellets were collected. Although forest plants contributed 28% of the fragment numbers and 41% of the fragment area in the pellets, coniferous tree browse accounted for only 2.5 and 5.0%, respectively. This supports the findings of other studies that red deer most likely has little impact on the forest dynamics in the Park. The spatial uniformity of faeces composition did not reflect the substantial differences in grassland vegetation between three study areas, probably because deer locally selected nutritious graminoids (particularly red fescue Festuca rubra) at patch level.