Copper(II)--mangostin complex was prepared by 2:1 molar reaction of ligand, -mangostin and copper(II) acetate in one-pot reaction. The resulting complex, [CuL 2 (H 2 O) 2 ] has been characterized by using spectroscopic techniques. Ligand and its metal complex were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumonia and Salmonella pneumoniae bacteria to assess on their antibacterial properties using Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs) method. The UV-Vis result showed that the complex has an octahedral geometry. The general formula [ML 2 (H 2 O) 2 ], in which L = -mangostin, is determined from UV-Vis, FTIR and CHNS data. Ligands were completely inactive against bacteria whereas the copper(II) -mangostin complex has significant action on bacteria, indicating that it has a good potential as bactericide.