As a result of the spread of International Parliamentary Institutions (IPIs), international organisations face crucial questions of representational design. We introduce a distinction between citizen-centred and state-centred IPIs in international organisations (IO). Drawing on original data, we show that, even though parliaments might seem likely to foster citizen representation in the international realm, they in fact often follow state-centred representational designs. We further find that citizen-centred IPIs are a near exclusive phenomenon of a few, democratic regional integration projects. Given the prevalence of state-centred representational designs, we conclude that IPIs’ potential to represent different cross-border communities, concerns, and conflict lines than intergovernmental IO bodies remains institutionally limited. IPIs are thus unlikely to challenge these bodies in similar ways as often observed in the relationship between the European Parliament and the European Union’s Council of Ministers.