Growth performance and nutrient digestibility were compared for two groups of 12 growing rabbits, fed a diet rich in starch (ST, 266 g kg - 1 dry matter (DM)) or a diet rich in digestible fibre (DF, 271 g hemicellulose + pectin kg - 1 DM), but with similar acid detergent fibre (ADF, 205 g kg - 1 DM) and lignin (50 g kg - 1 DM) contents. From weaning (day 28) to slaughter (day 72), the average daily feed intake (103 g day - 1 ) and weight gain (34.3 g day - 1 ) were not significantly different between the two groups. The total tract apparent digestibility of organic matter (mean 65.9%) and crude protein (73%) were not significantly affected by the diet. The digestible energy contents of the two diets were similar, although 50% of the starch was replaced by digestible fibres in the DF diet. The daily amount of neutral detergent fibre (NDF) or hemicellulose (HC) degraded was thus 60% higher in the DF group (13.6 g NDF day - 1 and 8.3 g HC day - 1 ), whereas the quantity of starch digested was reduced by 50% (9.7 g day - 1 ).The rate of passage of liquids and particles of the two diets was measured between the caecum and the rectum, for two further groups of nine rabbits fitted with a caecal cannula. The mean retention time (MRT) of the particulate marker ( 1 4 1 Ce) between caecum and rectum was 7 h, whereas for the liquid marker ( 5 1 Cr-EDTA) phase it was 30 h. The passage rates of particles were not affected by the diets; however, the caeco-colic MRT of the liquid phase tended to be lower for the DF diets (-7.1 h, P = 0.14).