One of the important aims of drug discovery for cancer is to find therapeutic agents from natural products that are effective and safe for cancer treatment. In the current study, an alkaloid, 2-acetyl-benzylamine, isolated from Adhatoda vasica, was screened for potent anticancer properties against leukemia cells. We used seven different types of leukemia cells such as CEM, NB-4, MOLM-14, Jurkat, IM-9, K562 and HL-60 for cytotoxic studies. 2-acetyl-benzylamine showed significant cytotoxic properties against MOLM-14 and NB-4 cells with IC₅₀ values of 0.40 and 0.39mM at 24h when compared to other tested cells, respectively. Apoptosis was confirmed by annexin V-FITC/PI kit using flow cytometry and confocal microscope in MOLM-14 and NB-4 cells. In addition, 2-acetyl-benzylamine induced cell cycle arrest at G2/M phase in MOLM-14 cells and G0/G1 phase in NB-4 cells. Apoptosis mechanism was confirmed by RT-PCR and Western blot analysis. Treatment with 2-acetyl-benzylamine decreased the Bcl-2 activity and increased the Bax expression; cytochrome c was released and caspases-3 was activated in MOLM-14 and NB-4 cells. Besides, 2-acetyl-benzylamine inhibited the expression of JAK2/STAT3 in MOLM-14 and NB-4 cells. In vivo administration of 2-acetyl-benzylamine inhibited the growth of MOLM-14 cells in xenograft mice model. Molecular docking study has been performed to investigate the binding mode and to estimate the binding energy of 2-acetyl-benzylamine with the active site of JAK-2, AKT1, FLT3 and Bcl-2. The above findings proved that 2-acetyl-benzylamine could be developed as a potential therapeutic agent against cancer.