Acute post-prandial hyperglycaemia may trigger acute increases in systemic inflammation and oxidative stress, potential risk factors for cardiovascular disease. We aimed to investigate the effect of both an oat-rich diet and standard dietary advice on glycaemic control, post-prandial glycaemia, inflammation and oxidative stress in volunteers with diet-managed type 2 diabetes. Method In a randomised cross-over design 30 volunteers with type 2 diabetes followed for two 8 week periods either an oat-rich diet or a control diet based on standard dietary advice. Volunteers attended at baseline, week 8 and 16. Measurements included basic clinical parameters, baseline blood tests followed by consumption of a standard test-meal with glucose, insulin and markers of inflammation and oxidative stress quantified during the post-prandial period. During each dietary period volunteers underwent a three day period of free-living continuous glucose monitoring (CGMS) during which time they kept a food diary. At the study end, the post-prandial response to an iso-energetic meal rich in oats was assessed. Results There were no diet-related differences in parameters of glycaemic control or post-prandial glycaemia based on CGMS data. Dietary intervention also had no effect on either the glycaemic or insulinaemic responses to the test-meal and there were no differences in the acute responses to the standard or oat-based test meals. Chronic intervention with the oat-based diet increased fasting adiponectin concentrations (P=0.06) and post-prandial ORAC concentrations (P<0.05) but had no effect on fasting CRP, ORAC, OxLDL or TBARS concentrations or the post-prandial response of CRP, adiponectin or TBARS to the standard test-meal. Following the oat-based test meal, adiponectin concentrations declined less (P<0.05) while CRP concentrations increased less (P<0.05) compared with the standard test-meal. Conclusion The oat-rich diet exerted anti-inflammatory and anti-oxidant effects in both the basal and post-prandial states independent of any effect on glycaemia. These findings may have implications for nutritional management of cardiovascular risk.