On the basis of sorption experiments up to 180 bar and 75 ^oC, the CO₂ solubility in an ammonium-type ionic polymer, such as poly(p-vinylbenzyltrimethyl ammonium tetrafluoroborate), is found to be much higher than that in an imidazolium-type ionic polymer, such as poly(1-(p-vinylbenzyl)-3-methyl-imidazolium tetrafluoroborate), which suggests that the cation type plays an important role in CO₂ sorption in polymerized ionic liquids. These two polymers remain glassy in the temperature and pressure ranges studied in this work. The CO₂ solubility increases with decreasing temperature and with increasing pressure, but it reaches a limiting value, beyond which it is insensitive to pressure.