Gibberellic acid (GA3) is one of the natural plant hormones. That plays versatile roles in the regulating a wide range of processes involved in plant growth and development. This work concerns the preparation, physicochemical characterization, and pharmacological properties of GA3 complexes with the ions Pt(II), Au(III), Ru(III), V(III), and Se(IV). These complexes were prepared with a 1:1 ratio at 65
C in neutral media using a solution of 5% NH3 at pH 7. Then, the complexes were characterized using several physicochemical techniques including an elemental analysis, molar conductance, magnetic moment, 1H and 13C NMR, IR, UVeVis, thermogravimetry, SEM, TEM, and XRD techniques. Finally, the complexes were assayed in vitro against two Gram-positive bacteria, two Gram-negative bacteria, and two human tumor cell lines. The results showed that GA3 - acts as a bidentate ligand and coordinating with the carboxylate group. Se (IV) and Au (III) complexes had a higher antibacterial activity than those of the conventional drugs, where the IC50 of the Pt(II) and Au(III) complexes for the cancer (HepG2 and MCF-7) cell lines were higher than those of the conventional drugs.