The use of carbon-13 Fourier transform nuclear magnetic resonance for quantitative analysis of the composition of methyl methacrylate-methacrylic acid copolymers has been investigated. It was found that in pyridine solutions of these copolymers, the resonances arising from acid carboxyl and ester carbonyl carbons were sufficiently resolved to allow the determination of relative Integrals. Compositional data obtained using 13C NMR compared favorably with those obtained by standard titration techniques. © 1977, American Chemical Society. All rights reserved.