Cinnamon is a traditional plant which is used as a spice, tea, for flavour and for the taste of food preparation. This spice possesses therapeutic properties to treat diabetes mellitus (DM), acting both as an anti-antioxidant and an anti-inflammatory mediator. There are different spices of cinnamon which can induce hypoglycaemic, protective and beneficial effects in DM, regulating blood glucose and lipid profiles. However, not much work has been done on the species, Cinnamomum burmannii. This study investigated the effect of aqueous C. burmannii extract on streptozotocin (STZ)-induced type 1 diabetic (T1DM) rats. Aqueous cinnamon extract (CE) of cinnamomum burmannii was adapted from Shen et al method (Biosci. Biotechnol. Biochem. 74(12), 2010). T1DM was induced by a single ip injection of STZ (60 mg/Kg body weight) to young adult male rats (125-149g) and maintained with 12 h:12 h light/dark cycle, at temperature and humidity controlled room. Two weeks following STZ-induction both diabetic and age-matched control rats were administrated daily with 150 mg/Kg bw of CE by gavage method during 11 weeks. Control groups (STZ and control) received the same volume of water. The study had ethical clearance of UCLAN and Veterinary Medicine Faculty of Portugal. Blood glucose level (BGL), body weight and food consumption were measured on a weekly basis. At the end of the experimental protocol, the biochemical parameters and the antioxidant status were determined in each rat. The results show that diabetic rats treated with CE showed no significant decrease (p>0.05) in BGL and food consumption compared with control group. However, body weight was significantly (ANOVA; p<0,05) increased in diabetic rats treated with CE (363.91±17,80 g) compared with control (257,68±18,08) group. The results also show that C. burmannii had no significant effect on either blood lipid profiles or on HbA1c in STZ-induced diabetic rats compared to control. However, the antioxidant status of C. burmannii was markedly improved in diabetic rats compared to control group, but this was not significant. The results suggest that aqueous C. burmannii extract possesses beneficial effects on T1DM rats through improvement in body weight and via its antioxidant properties. Nevertheless, the mechanism via which cinnamon exerts its anti- diabetic effect has to be clarified.