A subbituminous coal was oxidized with air at 150 °C on a fixed bed for 4 h and xanthated with carbon disulfide in a basic solution, at 30 or 5–10 °C. This xanthated coal was evaluated for the removal of Hg2+ and Cd2+ from 7,000 mg/L aqueous solutions; metal concentrations were determined by atomic absorption spectrometry. The ion exchange of the xanthated coal was compared against those of the original subbituminous coal, a sulfonated subbituminous coal, activated carbon, commercial activated carbon, and commercial synthetic resin. The commercial synthetic resin showed the highest exchange capacity (concentration factor 98 %) followed by the xanthated coal (concentration factor 96 %). The retention of cadmium on the sulfonated subbituminous coal was lower (exchange capacity 0.56 meq/g) than that of xanthated coals (1.85 ± 0.09 meq/g). Our xanthated coal showed a better Cd2+ removal (81 % against 15 %) than a non preoxidized 40-h-xanthated coal, which shows that oxidation of coal increased the amount of oxygenated groups which enhanced xanthation.