Complimentary medicines have been long investigated as new and alternative therapeutic options for treating type 2 diabetes mellitus because current drugs are associated with adverse drug reactions. The antidiabetic potential of the Zanthoxylum genus has been demonstrated previously. However, Zanthoxylum limonella (Dennst.)(ZL) has not been evaluated in any clinical trials. This study aimed to examine the inhibition of α-glucosidases in vitro and in vivo using ZL fruit extracts, thereby determining the reduction in blood glucose levels by using oral glucose and sucrose tolerance tests. The water extract of ZL fruits showed the greatest inhibition of a-glucosidases (IC 50, 1.04±0.08 mg/ml) than other extracts, particularly the dichloromethane extract and volatile oil. An acute toxicity test showed that the 50% lethal dose (LD 50) of the water extract was˃ 5,000 mg/kg. Regarding OGTT and OSTT, a single oral dose of ZL water extract (500 mg/kg BW) did not significantly reduce blood glucose compared to the control. In conclusion, the water extract of ZL fruits showed an inhibitory effect on α-glucosidase activity in vitro. However, it did not decrease blood glucose in mice. Further investigations should be performed to identify the active constituents of ZL fruit extracts.