Maleic anhydride-octene-styrene terpolymer has been modified with allylic alcohol and methylmethacrylate to prepare a new crosslinked functional polymer sorbent. The sorption behaviors of uranyl ions on the optimum sorption conditions were determined. The synthesized crosslinked polymer sorbent has a network structure and contains carboxylic acid, carbonyl, and ester groups, all of which are capable of interacting with metal ions. The maximum experimental sorption capacity of the sorbent for uranyl ions has been measured as 1.25 mmol g(-1). Langmuir and Freundlich isotherm constants and correlation coefficients for the present system have been calculated and compared. Uranyl ions are desorbed from the sorbent by treatment with hydrocholric and nitric acids at various concentrations. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 3570-3575, 2010