Terpolymer resins (8-HQDF) were synthesized by the condensation of 8-hydroxyquinoline (8-HQ) and dithiooxamide (D) with formaldehyde (F) in the presence of acid catalyst and using varied molar ratios of reacting monomers. Terpolymer resins compositions have been determined oil the basis of their elemental analysis and the number average molecular weights of these resins were determined by conductometric titration in non-aqueous medium. Viscometric measurements in dimethyl formamide (DMF) have been carried out with a view to ascertain the characteristic functions and constants. The UV-visible, FTIR, and proton nuclear magnetic resonance (H+ NMR) spectra were studied to elucidate the structure. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 3330-3335,2009