The distinction between strong and weak judicial review occupies a privileged place in comparative constitutional law. This article argues that it is necessary to generate a new typology that includes two other increasingly influential models. The two ‘new’ models can be identified as ‘strong basic structure review’ and ‘weak basic structure review’. The former, present in some common law countries such as India and Belize, not only provides judges with the ability to strike down legislation that is inconsistent with a particular constitutional provision, but also constitutional amendments incompatible with the principles on which the constitution rests. The latter model, weak basic structure review, currently present in some Latin American countries, also provides judges with the power to strike down ordinary and constitution-amending legislation, but gives ‘the people’, acting through a constituent assembly, the final word on the validity of any form of positive law. Finally, the article considers the possibility of the development of a fifth model in which even the constituent people would be bound by certain principles to be identified and enforced by judges.