In most European countries barley (Hordeum vulgare L.) is an important feedstuff for poultry, and its use could increase with changes in economic circumstances. Compared with wheat, barley contains more fibre and less energy. The nutritive value and suitability of this grain as a feedstuff for growing poultry are more or less affected by varying β-glucan concentrations. The anti-nutritive effects of β-glucan in the gastrointestinal tract of young chicks can be avoided by adding β-glucanase of microbial origin to barley-containing or barley-based diets, thus making this grain crop acceptable for broiler fattening diets. Feed mixtures for layers may contain a higher proportion of barley without negative effects on egg production. When formulating diets, the low content of linoleic acid has to be considered.