The nutritional effects of varying levels of leguminous leaf meal inclusion were investigated using 40 mixed weaner pigs of average weight 31·4 (s.d. 4·19) kg offered diets which included leguminous leaf meals (Acacia karroo, Acacia nilotica and Colophospermum mopane) over 18 days. The leaf meals were included at 100, 200 and 300 g/kg of dry matter. Leaf meals increased daily live-weight gain (P > 0·05) at low inclusion levels. They were also shown to increase food intake and food conversion ratio. There was an increase in digestibility of dry matter and protein at low inclusion level of leaf meals (P < 0·05), then a decrease in the digestibility as the level of leaf meals increased. Inclusion of leaf meals induced production of proline-rich proteins (molecular weights of 24 600, 54 000, 66 000 and 74 000 Da) in the parotid salivary glands of pigs but not in the mandibular glands (P > 0·05). The activity of hepatic microsomal uridine diphosphate glucuronyl transferase increased significantly (P < 0·05) for pigs offered diets supplemented with A. nilotica and C. mopane but not with A. karroo (P < 0·05). Intestinal parameters (crypt depth, villus height and villus-crypt ratio) were not significantly affected by leaf meal inclusion (P > 0·05) except crypt depth at the proximal position of the small intestine, which decreased with increasing leaf meal levels (P < 0·05).