Itaconic acid (methylene succinic acid)-acrylamide (IA-AAm) copolymers were synthesised with solution polymerisation by using potassium persulphate. The potentiometric titration method was used to determine the copolymer compositions. The results were evaluated by various methods. The monomer reactivity ratios were found to be r(IA) = 0.99 +/- 0.04, r(AAm) = 0.58 +/- 0.02 with the Fineman-Ross, r(IA) = 1.05 +/- 0.10, r(AAm) = 0.62 +/- 0.06 with the Kelen-Tudos, and r(IA) = 1.36 +/- 0.11, r(AAm) = 0.77 +/- 0.06 with the Tidwell-Mortimer methods. As expected, IA is found to be the more reactive monomer in IA-AAm copolymers. (C) 2000 Elsevier Science Ltd. All rights reserved.