Background: Diabetes mellitus is one of the leading chronic diseases worldwide. In patients with poor glycemic control, high blood glucose level may lead to other life-threatening complications. Pandanus amaryllifolius Roxb. (PA) leaves are used in traditional medicine for the treatment of diabetes. Objective: This study evaluated the effect of crude extract from PA leaves on blood glucose level and the hypoglycemic mechanisms. Materials and Methods: Thirty healthy volunteers were asked to drink PA tea (test-group) or hot water (control group) 15 min after glucose loading (75 g) in a standard oral glucose tolerance test. To study hypoglycemic mechanisms, PA leaves were extracted using two different methods. Method 1; dried PA leaves were extracted with distilled water at 90°C for 15 min, and method 2; dried PA leaves were extracted with 95% ethanol. Both PA extracts were tested for α-glucosidase enzyme inhibition, insulin stimulation, and glucose uptake stimulation. Results: The average of blood glucose level in the control group was 5.55 ± 0.98 mmol/l, while in PA treated group was 6.16 ± 0.79 mmol/l which were statistically different (P < 0.001). The results of antihyperglycemic mechanism showed that PA extracts, prepared both methods, could inhibit α-glucosidase enzyme and induce insulin production in rat pancreatic cell (RINm5F) in dose-dependent manner (P < 0.05). Conclusions: The knowledge gained from this research can be used as a basis for a new drug discovery for the treatment of diabetes.