Abstract. The common dormouse (Muscardinus avellanarius) feeds on both vegetable food and food of animal origin. The dormouse has a varied diet, which depends upon latitude and nutritional plant species available and follows a strongly seasonal pattern. The main vegetable food sources are flowers in spring, berries in summer, nuts and soft fruits in autumn, but dormice also use many other food sources. Among vegetable foods, generative parts of plants (flower-buds, catkins, flowers, berries, and seeds) are preferred, whereas vegetative parts (leaf-buds, leaves, and shoots) are only subsidiary foods for these rodents. In spite of tannins that oak acorns contain, they may play an important part in the diet of dormice. During periods of scarcity of suitable vegetable food (e.g. in late spring and early summer), dormice use food of animal origin, primarily insects and bird eggs. Feeding on food of animal origin is expected to be more important in suboptimal habitats with a low diversity of nutritious plants. Some feeding activities attributed to the common dormouse (killing and eating of nestlings and even adult birds, hoarding of food supplies in autumn), may actually be performed by other animals (other dormouse species, Apodemus mice).