This paper proposes a comparative inquiry on differences and similarities between two bodies of administrative law: the administrative law of the Roman Catholic Church – an institution that combines elements typical of legal-rational authorities with a number of charismatic and traditional features – and the administrative laws of those States and regulatory systems beyond the State that are mainly legal-rational in nature. The comparison between canon administrative law and the administrative laws of mainly legal-rational regimes is developed by considering four inter-connected aspects: i) their process of emergence and development; ii) their constitutive «materials»; iii) their position within the legal order; iv) their overall explanatory paradigms. The inquiry reveals that canon administrative law is based on a complex combination of religious and statal elements, which gives rise to an unstable regulatory framework crossed by several internal tensions. On a more general level, the comparative inquiry sheds some light on the links between the features of administrative law and the types of power (legal-rational power, charismatic power and traditional power) that the administrative law serves and regulates.