We report here inclusion complex formation between gamma-cyclodextrin (gamma-CD) and stereoregular poly(methyl methacrylate)s (PMMAs). gamma-CD was found to form an inclusion complex with isotactic (it) PMMA more effectively than with syndiotactic (st) PMMA. The formation of an inclusion complex between gamma-CD and st-PMMA was strongly influenced by the amount of gamma-CD added, and the addition of an excess amount of gamma-CD was required for gamma-CD-st-PMMA complex formation.