Because of the unique characteristics of ionic liquids, novel polymer-containing materials in which ionic liquids play an important part are currently under intense scrutiny. The ionic liquid may be used as a medium in which polymerizations take place or into which a polymer may be dissolved or dispersed to enable a further chemical transformation or materials processing step to be carried out. Ionic liquid functionality may also be incorporated into the polymer itself, by the use of suitably derivatized monomers, by a post-polymerization reaction or simply by the formation of a composite comprising (at least) a polymer and an ionic liquid. The use of ionic liquids in such chemical and material processing necessitates an appreciation of their effect on reactivity and the forces that govern solubility and solvation. These topics are at an early stage of investigation, none more so than in respect of polymers and polymerization. This review surveys published material up to July 2006 relevant to polymer solubility and solubilization in ionic liquids.