Diabetes mellitus is a chronic endocrine disorder of carbohydrate, fat and protein metabolism characterized by an increase in both fasting and postprandial glucose level and it has been reported to be the major cause of mortality worldwide. There is an alarming projection of 471 million people with the disease by the year 2035. Diabetes is grouped into two forms; type 1, insulin dependent diabetes mellitus and type 2, non- insulin dependent diabetes mellitus. Type 2 is the major form accounting about 90% of cases worldwide. In type 2 diabetes mellitus (DM2), postprandial hyperglycemia is important in the development of the disease; Current treatment for Type 2 diabetes remains inadequate so prevention is preferable. The major strategy for the management of Type 2 diabetes is to decrease postprandial hyperglycemia. The ?-glucosidase inhibitors, such as acarbose, have been used in the clinic to control blood glucose increase, especially postprandial, in DM2.Herbal medicine is predominantly available for the treatment of diabetes and the main advantages of the use of herbal drugs are effectiveness, safety, and acceptability. The mechanism of action of these medicinal plant of its products involve retarding the absorption of glucose by inhibiting the carbohydrate hydrolyzing enzymes, such as pancreatic amylase and ?-glucosidase and through the inhibition of these enzymes, medicinal plants can effectively control the postprandial rise in blood glucose. Several medicinal plants have a high potential in inhibiting ?-amylase enzyme activity.Annona muricata (A. muricata) is a tropical plant species belonging to family Annonaceae and known for its many ethnomedicinal uses. All parts of Annona are used in natural medicine in the tropics. It is considered to be a good source of natural antioxidants for various diseases. Traditionally, the leaves are used for headaches, insomnia, cystitis, liver problems, and diabetes, antitumor, anti-inflammatory. The health benefits of this plant have been attributed to their unique phytochemical composition.There is, however, a paucity of information that demonstrates the comparative ?-amylase and ?-glucosidase inhibitory properties of different extracts and fractions, of the various parts of the plant (fruit-pulp, leaf, stem-bark and root-bark) with relation to its anti-diabetic activity. Hence, the present study was carried out to investigate the comparative ?-amylase and ?-glucosidase inhibitory potentials of methanolic, ethyl acetate and dichloromethane extracts of the fruit-pulp, leaf, stem-bark and root-bark of Annona muricata and also to determine the possible modes and mechanisms of inhibition of these enzymes by these extracts. The justification for this research is the severe gastrointestinal side effects such as abdominal pain, flatulence and diarrhea that have been reported in the patients after the use of conventional drugs, so that the identification of natural interventions through the use of plants like Annona muricata, becomes beneficial due to their very minimal or absence of negative side effects.