Two sulfadiazine azo-azomethine dyes containing two active coordination centers and their bi-homonuclear UO2 (II)-complexes were synthesized for potential chemotherapeutic use. The ligands were prepared, starting from the coupling of sulfadiazine dizonium salt with acetylacetone, followed by condensation with ethylenediamine and 1,6-hexanediamine (HLI and HLII) using a modified literature procedure. The structures of the ligands and their UO2 (II)-complexes were elucidated by conventional and thermal gravimetric analyses, molar conductivity, magnetic susceptibility, and IR, UV-Vis, H-1 NMR, and mass spectra. The analytical and spectral data supported the binuclear formulation of the complexes with a 2:1 metal to ligand ratio and octahedral geometry. The molar conductance values of the UO2 (II)-complexes revealed their nonionic character. The ligands and their complexes were screened for their antibacterial activities towards the gram-positive Staphylococcus aureus and the gram-negative Escherichia coli, as well as their antifungal activities against Aspergillus niger and Candida albicans, in order to assess their antimicrobial potential. The results showed that metallization increases antimicrobial activity compared with the free ligands.