Terpolymer (BPEDF-III) has been synthesized using the monomers 2, 2’-biphenol, ethylene diamine and formaldehyde in 3:1:4 proportion in the presence of 2M HCl as a catalyst. The number average molecular weight of this terpolymer has been determined by conductometric titration in nonaqueous medium. Viscometric measurement in dimethylformamide has been carried out with a view to ascertain the characteristic functions and constants. Elemental analysis confirms the stoichiometry of the BPEDF-III terpolymer whereas the structure has been elucidated on the basis of IR, NMR, UV-Visible spectral studies. The antibacterial activities of the terpolymer were screened on various bacteria. The synthesized polymer has shown excellent antibacterial activities as compared to the standard Ciprofloxacin.