Two experiments were conducted with 270 growing geese fed complete diets differing in the source and content of carbohydrates and structural fractions. The experimental diets contained similar levels of crude fibre provided by different proportions of one of the following components: corn (50%), dried grass (20%), oats (65%), beet pulp (31%), rye (50%), barley (60%), field bean, pea or rapeseed meal (20% each). The level of the crude fibre in the experimental diets was twice as high as in the control diet. The digestibilities of the structural fractions in the smali and large intestine were determined with the indicator method. Morphological changes in the walls of intestine were examined in birds slaughtered at 1 and 2 h after feeding. Feeding diets containing large proportions of components rich in cellulose and hemicellulose such as oats, beet pulp and dried grass caused an increase on the thickness of the wall mainly on the muscular part of the small and large intestine. Longer villi were observed in the large intestine of birds fed the diet which contained beet pulp. Feeding a large proportion of rye containing pentosans resulted in an increase on the thickness of the mucous wall; feeding a diet containing rapeseed meal resulted in a decrease on the thickness of the intestinal wall. Small differences were found between the extent of digestion of structural substances in the two parts of the intestine. Cellulose was digested, depending on the composition of the diet, by 20 to 40%, ADF by 18 do 38% and hemicellulose by 40 to 57%.