Piper longum fruits oil in Binh Dinh, Vietnam was obtained via steam distillation with oil collection efficiency reaching 1.01%. The chemical compositions of the essential oil from Piper longum fruits in Binh Dinh, Vietnam is determined via the GC-MS method that includes 35 components (99.68%), among which the main components are caryophyllene (10.78%), 3-heptadecene (9.95%), zingiberene (9.54%), germacrene D (8.96%), pentadecane (8.76%), heptadecane (8.73%), β-bisabolene (5.98%), humulene (5.80%), (E)-5-tetradecene (2.73%), α-bisabolene (2.47%), tridecane (2.35%). The essential oil of Piper longum in Binh Dinh, Vietnam also showed weak anti-acetylcholinesterase activity with IC50 (µg/mL) = 164.55±13.79 compared to galantamine as a positive control and potent nitric oxide suppressing activity with IC50 (µg/mL) = 13.02±0.29 compared to dexamethasone as a positive control.