A novel ten coordinated binuclear hydrated praseodymium(III) ethylenediaminetetraacetate with phenyl hydrazine has been synthesized and characterized by analytical, spectral and thermal techniques. The structure of the compound determined by X-ray crystallography reveals the binuclear nature of the complex with ten coordination around Pr(III) ions. Neutral phenyl hydrazine molecules present outside the coordination sphere and four inner sphere water molecules found to occupy the coordination sites (each Pr(III) ions possessing two coordinated water molecules). Among five more water molecules, four are involved in hydrogen bonding with phenyl hydrazine and EDTA4− and hence present in the second sphere. The remaining water molecule is present as bulk water. Interestingly, in the present case EDTA4− ions act as heptadentate ligand with one acetate group from each EDTA4− ion showing novel tridentate bridging behavior. The biological studies such as antioxidantal, antiviral and cytotoxicity studies reveal that this complex indeed shows promising activity.