<bold>The Reception of German Administrative Law in the Spanish Legal System</bold> At present, German public law exerts a significant influence on Spanish law. Traditionally, Spanish public law has always been wide open to foreign law. From a historical perspective, this was not a peculiarity of Spanish law in the <italic>Ancien Régime</italic>, a time when European States shared the same legal institutions, primarily built on common law. For several different reasons, the nineteenth century brought with it an increasing differentiation of the nascent national administrative and constitutional laws in Europe. Some countries, like Germany and France, shut down their public laws to foreign influences. The same is not true of Spain which continued, right up to the present day, to remain wide open to influences from other countries. The traceable influence of both German scholarly literature and German positive law are good examples of the phenomenon described. The extent of the influence is so wide that it cannot be rightly described as a Spanish-German comparative methodology, but as the reception of German public law in Spain. This study aims at a theoretical analysis of this legal reception. To this end, a primary distinction is drawn between theoretical and normative reception, as both realities do not usually go together. The following exposition is based on two axes: the historical stages of the reception, and the reasons for such wide influence. Historically speaking, a distinction is drawn between the initial methodological reception (early twentieth century); the intense reception since the adoption of the current Spanish Constitution in 1978 (in many respects comparable to the Basic Law for the Federal Republic of Germany); and the current reception that takes place within the framework of European Union law. As for the reasons for the reception, this study distinguishes between final causes (the intrinsic suitability of German law to be exported), intermediate causes (the various ways of academic and institutional connection between Germany and Spain), and final causes (the suitability of Spanish law for receiving foreign influences, especially from Germany).