The objective of this study was to examine the effects of increasing doses of Ceylon cinnamon’s aqueous extract on fasting plasma glycemic and lipidemic profiles, as well as body weight gain, food intake and food efficiency ratio (FER) in alloxan-diabetic rats. Cinnamon extract was administered to rats at different dosages (200, 400, 600 and 1200 mg/kg bw) for thirty days followed by a fifteen day wash out period. After thirty days, the administration of diabetic rats with the lowest dose (200 mg/kg bw) of cinnamon extracts was the most efficient in affecting significant (P < 0.05) reduction in the levels of fasting blood glucose (FBG), but no hypoglycaemic activity was observed in the untreated diabetic control rats. Moreover, cinnamon treatment significantly (P < 0.05) lowered the serum levels of total cholesterol (TC), high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol and triglycerides (TG), compared with the diabetic positive control (PC) rats. The observed hypoglycemic and hypolipidemic effects of cinnamon extracts in diabetic rats were associated with significant improvements in body weight gain, FI and FER. While, after the 15-day wash-out period, the level of FBG, TC, LDL and TG gradually increased, they were still lower than that in the diabetic PC group of rats. It can be concluded that cinnamon extract exhibits a modulatory role of glycemic and lipidimic profiles in diabetic rats.