The nutritive value of 8 semisynthetic and 2 natural diets containing whole or dehulled white lupin seeds from three low-alkaloid varieties was evaluated in two experiments. Substituting dehulled seeds for whole seeds lowered dietary fibre in the semisynthetic diets from 112.7-122.6 to 63.3-65.0 g/kg. However, this did not lead to increased intake. True protein digestibility coefficients of the diets were similar (85.2-87.7%), irrespective of the lupin variety and presence or lack of seed hulls. A slight increase in the protein efficiency ratio (PER) from 2.16-2.19 (diet with whole seeds) to 2.33-2.38 (diet with dehulled seeds) was noted. Dehulling white lupin seeds did not improve protein digestibility or PER of natural diets containing cereals.