This article discusses theories and practice of parliamentary institutionalization. Further, it introduces issues that have importance for the practice of legislative institutionalization in post-communist parliaments and require more scholarly attention. This article discusses internal and externalfactors to the process of legislative institutionalization, such as parliamentary party groups, committees, and legislative-executive relations. These issues will be further discussed in the upcoming Special Issue of the Journal of East European and Asian Studies. This article discusses a conceptual framework and offers some of the most important issues for readers’ initial consideration.