Binary and ternary palladium and platinum complexes were synthesized from [MCl 4 ] 2¡ with certain heterocyclic ligands containing nitrogen and oxygen donors and a secondary ligand (pyridine or bipyridine). Complexes were characterized by elemental analysis, mass, IR, and 1 H NMR spectroscopy. Biological activities of ligands and complexes against the Escherchia coli and Staphylococcus aureus bacteria, and the two fungi Aspergillus flavus and Candida albicans were screened. The cytotoxicity of the two complexes [Pt (PCA)(Py)(Cl)]Cl and [Pt(PCA)(m-Cl) 2 (Bpy)]Cl 2 were checked as antitumor agents on two breast cancer and liver carcinoma cell lines. They exhibited higher in vitro activities toward the tumors relative to cisplatin.