This paper briefly deals with the relation between the quality of legislation and the decision-making practice of the administrative authorities. The clear terminology, understandable formulations, well-structured systematics, detailed and in the correct context expressed substantive law institutes, clear process adjustment and precisely formulated empowering provisions as well as composability are among the parameters that facilitate the interpretation and application of legal regulations and which can affect the legality, and even constitutionality of public administration decisions.Examples can show that positive law often does not meet these requirements.