OBJECTIVE: To determine whether diet supplementation with arabinoxylan-rich (AX)-fibre from wheat improves glycaemic control in Type II diabetes. DESIGN: Randomized, crossover intervention trial. SETTING: Monash Medical Centre. SUBJECTS: A total of 15 subjects with Type II diabetes. INTERVENTIONS: Over two 5-week periods, subjects supplemented their usual diet with control bread and muffins (50% whole wheat, 50% white flour) (control diet) or with AX-bread and muffins (50% whole wheat, 36% white flour, 14% AX fibre) (AX diet). Subjects completed a 7-day food diary. At 0 and 5 weeks, venous blood was collected for determination of fasting and 2 h glucose, insulin, fructosamine and blood lipids. Blood pressure, body weight and body fat were also determined. A 24 h faecal sample, from 12 subjects, was weighed and analysed for faecal polysaccharide as a marker for dietary compliance. RESULTS: Control and AX diets were similar except the AX diet supplied an additional 15.1 (12.0-18.5) (mean (95% confidence intervals)) g/day dietary fibre (P=0.000). Consumption of the AX diet increased faecal output by 61.5 (0.2-122.8) g/day (P=0.05) on a wet weight basis and significantly lowered fasting and 2 h plasma glucose, 2 h insulin and serum fructosamine (P=0.002, 0.000, 0.015, and 0.02, respectively). Blood lipids, body weight, fat mass and blood pressure remained unchanged. CONCLUSION: A supplement of 15 g/day of AX-rich fibre can significantly improve glycaemic control in people with Type II diabetes.