Diabetes mellitus is a syndrome that is widely distributed in Iraq with its two major types: type-1 and type-2. The aim of this study to find new agents associated with fewer side effects for the therapy of non-insulin dependent diabetes mellitus (NIDDM) patients. Five medicinal plants were involved in the experimental study in rabbits. The aqueous extract of Cinnamomum verum, Nigella saliva and Olea europea was found to produce a significant reduction in blood glucose levels of normal and alloxan induced diabetic rabbits with the most effective dose of 0.5g/Kg. Whereas Capparis spinos produced non-significant reduction in blood glucose levels. The data indicated that the combination of glibenclamide with the aqueous extract of Cinnamomum verum and Nigella sativa produce a significant decrease in plasma glucose levels of diabetic rabbits as compared with the diabetic control and diabetic that treated with insulin throughout the four weeks of the treatment. The aqueous extract of Cinnamomum verum, Coriandrum sativum, Nigella sativa and Olea europea was also found to produce a significant reduction in ,, plasma triglyceride levels of the diabetic rabbits throughout the four weeks of the treatment. In the mean time, all of the treatments cause a significant decrease in plasma cholesterol levels of the diabetic rabbits, from the first week to the last week of the treatment except the aqueous extract of Cinnamomum verum, Coriandrum sauvum, Olea europea and glibenclamide singly or in combination with Nigella sativa Using Coriandrum sativum singly or in combination with glibenclamide, and Capparis spinos produced non-significant reduction in raised plasma GOT and GPT levels in diabetic rabbits. Whereas the other treatments produced a significant reduction in plasma levels of these enzymes. The results also showed that the different treatments of diabetic rabbits produced a significant reduction in plasma creatinine levels except that with glibenclamide, Capparis spinos, Coriandrum sativum singly or in their | combinations and the combination of glibenclamide with Olea europea . The hypoglycemic effect of Cinnamomum verum and Nigella sativa was compared with the effect of oral hypoglycemic drugs (glibenclamide, metformin and repaglinide) in patients with NIDDM. There was a significant decrease of the glycosylated hemoglobin (HbAlc) in all the groups of patients after six weeks of treatment except that with glibenclamide and its combination with metformin. It appears that the HbAlc level was more reliable than the fasting blood glucose level in long-term of glycemic control. Lipid profile was the second index of overall metabolic control in patients involved in this study. The results revealed that all the treatments except that of glibenclamide reduced the total cholesterol in diabetic patients. In the mean time all the treatments reduced triglyceride levels and VLDLcholesterol levels in diabetic patients with exception of repaglinide and Cinnamomum verum. The LDLchlolesterol was reduced in all groups of patients but HDLcholesterol levels was increased by all treatments except that with repaglinide and Cinnamomum verum. Therefore the risk factor (total cholesterol / HDLcholesterol) was decreased by all treatments involved in this study. Our data indicated that Repaglinide, Cinnamomum verum and Nigella saliva were more effective than glibenclamide and metformin in controlling blood glucose in diabetic patients. Also repaglinide was the less associated with the risk of hypoglycemia than glibenclamide and metformin. The treatment with Cinnamomum verum or Nigella saliva showed a significant decrease in the numbness and paraesmesiae in the feet and hands in about 8% with no side effects except gastric burning in about 3.33% and 1.66% of patients respectively. There were no changes in the liver and renal function in diabetic patients who treated with different agents involved in this study. In conclusion, Cinnamomum verum and Nigella sativa singly or in combinations with oral hypoglycemic drugs were effective, safe and cheap in the treatment of NIDDM patients in Iraq.