Di-n-butyl itaconate (DBI) was polymerized at 50 degrees C in a 3 moll(-1) benzene solution using 2,2’-azobisisobutyronitrile (AIBN) as a free-radical initiator. Kinetic constants for DBI were obtained as follows : k(p)/k(t)(1/2) = 0.021 mol(-1/2) 1(1/2) s(-1/2), 2fk(d) = 3.62 x 10(-6) s(-1). Copolymerization reaction between DBI and methyl methacrylate (MMA), under the same experimental conditions, was carried out and the values of r(DBI) = 0.717 +/- 0.11 and r(MMA) = 1.329 +/- 0.09 were found for the reactivity ratios. Applying the Q-e scheme led to Q = 0.61 and e = 0.62 for DBI. Overall copolymerization rate coefficients have been analysed on the basis of terminal and penultimate effects on the propagation reaction. These parameters as well as the copolymer composition are not affected by total monomer concentration.