Pastinaca sativa belonging to the family Apiaceae, is a tropical tree used in many countries as a herbal drug for the care of diabetic patients. However, the methodical rationale for this medical use is very limited. The aim of this analysis was to examine the antidiabetic activity of the Pastinaca sativa methanolic extract and the possible mechanisms underlying that activity. The extract hypoglycemic behavior was investigated in typical diabetic rats induced with alloxan. Finally, an effect of the Pastinaca sativa extract (Crude extract of Pastinaca sativa-CEPS) on the activity of α-amylase and α-glucosidase was examined in vitro. CEPS showed IC50 equal to 91.69 ± 1.5 μg/mL for α-amylase enzyme inhibition activity. Normal acarbose (control) demonstrated IC50 equal to 83.25 ± 1.28 μg/mL. CEPS displayed IC50 values of 88.05 ± 1.25 μg/mL for α-glucosidase enzyme. Under similar laboratory conditions, acarbose displayed an IC50 value of 51.00 ± 1.23 μg/mL. CEPS exhibited IC50 less than 100μg/mL would be considered as healthy. The extract at 400 mg/kg greatly decreased the region under the blood glucose level curve in a typical rats test for oral glucose tolerance. A single dose of the extract decreased significantly in the alloxan-induced diabetic model, similar to glibenclamide (standard), from 208.33 mg/dl to 106.38 mg/dl at 200 mg/kg CEPS and from 209.82 mg/dl to 111.65 mg/dl at 400 mg/kg CEPS. These findings were comparable with 0.5 mg/kg of glibenclamide indicating a substantial decrease from 205.55 mg/dl on 7th day to 84.88 mg/dl. The Pastinaca sativa methanolic extract possesses strong antidiabetic activity in vivo. Besides, the extract has also been shown to have a significant inhibitory activity of αamylase and α-glucosidase, which might lead to its anti-hyperglycemic function when used in diabetic patients.