Few studies have compared the pregastric and caecal digestion of hamsters. Mature Syrian hamsters (Mesocricetus auratus) were fed a diet containing crude protein and fibre at 225 and 64 g/kg, respectively. In the pregastric digesta, the pH, volatile fatty acids (VFA), lactate and ammonia N concentrations were 5.91 +/- 0.97, 43.1 +/- 12.9 +/- mol/g, 19.2 +/- 8.0 +/- mol/g and 2.46 +/- 1.16 mg/g, respectively. The corresponding values in the caecal contents were 6.41 +/- 0.25, 92.1 +/- 12.2 +/- mol/g, 6.9 +/- 1.0 +/- mol/g and 0.28 +/- 0.08 mg/g, respectively. Acetate was the primary VFA, followed by propionate in the forestomach and butyrate in the caecum. In the caecal contents, a very small amount of methane was produced. The number of total bacteria determined by real-time PCR averaged 2.31×10(9)/g and 1.57×10(10)/g in the pregastric and caecal digesta, respectively. In the pregastric digesta, bifidobacteria and Bacteroides sp. were present at 1.57×10(7)/g and 4.02×10(7)/g, respectively. In the caecal contents, the numbers of bifidobacteria and Bacteroides sp. were 1.01×10(8)/g and 1.46×10(8)/g, respectively. The caecum appears to be more important in hamsters than the forestomach, both in terms of its greater size (3.39 +/- 0.63 g vs. 1.59 +/- 0.70 g) and greater microbial activity.