The article analyses the impact that the diminutive size of the four continental Europe micro states has upon their constitutional arrangements and their approach toward continental integration mechanisms. Generally speaking, the international commitment toward integration mechanisms is one of the distinguishing traits of micro states. It may seem a paradox, but actually the international dimension is much more strategic for micro than for macro states. However, being micro territorial enclaves demanded certain ability from the part of European micro states when managing foreign relations in order not to be swallowed by their macro neighbours. Therefore, they carried out for centuries a cautious policy of ‘guarded openness’, trying to strike a balance between the maintenance of their traditional institutions and the need to interact on a continental scale. Constitutional systems that at a first glance are unusual may be an obstacle to integration and thus have to be reformed. However, not too much, because otherwise the whole system may implode if deprived of its original constitutional balance. The protection of national tradition and identity is conservative, in the sense that it arises from the necessity of self-preservation, rather than from ideology. The article claims that the ambivalent approach of continental Europe micro states have when interacting with macro states within the Council of Europe and the EU directly derives from their diminutive size. Furthermore, the relevant role played by the diminutive size is proved by the fact that recently the EU adopted a specific micro states approach. Hence, the article also aims at investigating how they try to strike a balance between the commitment toward self-preservation – ie their constitutional identity – and the commitment toward continental integration mechanisms.