Free-radical solution terpolymerization of acrylamide, acrylic acid, and acrylonitrile was carried out in a mixture of dimethylformamide and water (60 : 40, v/v) at 85 degrees C using benzoyl peroxide as the initiator. The polymers were characterized by elemental analysis, IR, H-1-NMR, TGA, and viscosity measurements. Elemental analysis data were used to evaluate the terpolymer composition. The reactivity ratios were determined by Fineman-Ross and Kelen-Tudos methods. The reactivity ratios (r) for the copolymerization of (1) acrylic acid + acrylonitrile with (2) acrylamide was found to be r(1) = 0.86 +/- 0.09 and r(2) = 1.93 +/- 0.03, respectively, by the Kelen-Tudos method. The Fineman-Ross method yielded a value of r(1) = 0.86 +/- 0.05 and r(2) = 1.94 +/- 0.09, respectively. The activation energy values for various stages of decomposition were calculated from TGA analysis. Voluminosity (V-E) and the shape factor (nu) were also computed from the viscosity measurements in different ratios of the solvent mixture.