The objective of the present study was to evaluate effects of condensed tannins in faba beans (Vicia faba L.) on morphological and functional variables of the small-intestinal mucosa of piglets. In an experiment with young piglets (8–17 kg body weight), fed on either a control diet or a diet containing 200 g/kg of low- or high-tannin faba bean hulls (with < 0·10 and 3·3% catechin equivalents of condensed tannins respectively), morphological and functional characteristics of the jejunal mucosa were determined. Results of the study showed that the morphological variables of the mucosa of the three groups of piglets were similar. Also, no changes due to dietary tannins were observed in sucrase (EC 188.8.131.52)–isomaltase (EC 184.108.40.206) activity in homogenates of mucosa plus submucosa. However, aminopeptidase (EC 220.127.116.11) activity in these homogenates in the proximal part of the small intestine of the animals of the group fed on the high-tannin diet was significantly lower than that in the animals fed on the control diet or the diet with low-tannin hulls (P < 0·05).