Three mixed ligand complexes of sulphamethoxazole and citric acid have been synthesized using Mn(II), Fe(III) and Ni(II) chlorides. The complexes were characterized by elemental analysis, melting point, conductivity test, magnetic measurement, UV-Visible and infrared spectroscopy. The infrared spectra data revealed that the ligands act as bidentate, in which citric acid coordinate through C=O of the carboxyl and oxygen of the hydroxyl groups, while sulphamethoxazole coordinates through nitrogen atom of the primary amine group and O=S=O of the sulphonyl group. The result of the elemental analysis was consistent with the proposed pattern for the complexes, while the melting point determination confirmed that the synthesized compounds were pure. Antibacterial activity of metal complexes were screening against five strain bacteria microorganism of g(+)Pseudomonas aeruginosa, Eschericia coli, g(+)Klebsiella pneumonia, g(+)Staphylococcus aureus and g(+)Candida using Muller Hinton diffusion method. The result showed that the overall zone of inhibition against bacterial isolate follows an increasing order of priority Fe(III)˃ Ni(II)˃ Mn(II) complexes.