Introduction: Diabetes Mellitusi is a common endocrine and metabolic disease. It ischaracterized by hyperglycemia and abnormal metabolism of the lipid, carbohydrate, and protein that are caused bydeficiency of insulin or defective insulin action or both. Today,it is considered as one of the major health problems in the world. Ocimum basilicum (Basil) is one of the most widely grownpopular herbs in the world. It contains a large number of phytochemicals which have many significant health and nutritionalbenefits. It belongs to Lamiaceae (Mint family)and possesses marked anti-hyperlipidemic, anticancer and antioxidant activity.  Objective: The aim of this work is to evaluate the possible protective effect of Ocimum basilicum administration on the induceddiabetic colon of adult male albino rats.  Materials and Methods: Sixty adult male albino rats were used in the present study. They were divided into four groups, Group I (control group), Group II (ocimum basilicum received group), Group III (diabetic group) and Group IV (diabetic with ocimum basilicum group). After four weeks, the animals from all groups were anaesthetized and the blood samples were collected for biochemical study. The colon was dissected and the specimens were subjected to histological, histochemical, immunohistochemical and scanning electron microscopic studies.  Results: Diabetic colon revealed a significant increase in the depth of intestinal crypts and number of goblet cells with marked biochemical and histological alterationsas increase in plasma level of MDA, shedding of the surface mucosa and small size Aeurbach's myenteric plexus. Administration of Ocimum basilicum in rats with diabetes mellitus has ameliorating effect on the histological, biochemical and morphometric abnormalities of the colonic tissue.  Conclusion: Ocimum basilicum has a protective effect on the histological, biochemical and morphometric changes of the colon of diabetic rats. It has also a protective effect on the intestinal myenteric nerve plexus.