The present study was undertaken to evaluate the potential of Ficus deltoidea to inhibit the enzyme, α-glucosidase in the small intestine, as this is known to be an antidiabetic mechanism. The results of the in vitro study had shown that hot aqueous, ethanolic and methanolic extracts of Ficus deltoidea inhibit rat intestine α-glucosidase activity significantly, in a concentration dependent manner. The IC50 values of these extracts are 4.15, 2.06 and 1.72 mg mLG1, respectively. From a study of the enzyme kinetics, all extracts exhibited a mixed-type inhibition mechanism against the activity of α-glucosidase. In an animal study, all extracts, when used at a dose of 1000 mg kgG1 b.wt., reduce postprandial hyperglycemia following sucrose administration. This was true in normal and in diabetic rats, as shown by the significant attenuation of the value of AUCGlucose compared to the control group. The methanolic extract is the most potent inhibitor of α-glucosidase, followed by the ethanolic and hot aqueous extracts. We suggest that the inhibition of α-glucosidase in the small intestine in part mediates the antidiabetic property of Ficus deltoidea.