Plants are source of medicinal compounds. Salam leaf or Indonesian bay leaf (Syzygium polyanthum (Wight) Walp) from the family of Myrtaceae are widely used as herbs and spices for cooking (culinary) and as traditional medicine for diabetes, diarrhea, and hypertension. Indonesian bay leaf contains many compounds including essential oils, tannins, and flavonoids. In this study, 70 % and 96 % ethanol extracts of bay leaf obtained from the garden in Research Center for Science and Technology (PUSPIPTEK), Serpong, Tangerang Selatan, Indonesia were tested in vitro according to α-glucosidase inhibition method to determine antidiabetic activity and to scavenge DPPH free radicals in order to determine antioxidant activity and toxicity on Brine Shrimp Lethality Test (BSLT). The results showed that extraction of Indonesian bay leaf by using 70 % and 96 % ethanol extracts have anti diabetic activity (97.37 % and 95.51 % α-glucosidase inhibition) and antioxidants activities (89.66 % and 69.18 % DPPH inhibition), respectively and have very low toxic effects on brine shrimp larvae (LD50 > 1,000 μg/mL).