Abstract :In this article, the author deals with the topic of the principle of proportionality and its application in individual institutes of criminal law. The aim of the article to define the concept of proportionality in the context of criminal law and its application in substantive criminal law as a principle in imposing penalties on the offender and in the context of procedural law as a principle directly defined in §2 para. 2 of the Criminal Procedure Code and application in several procedural institutes such as institute of summoning, showing and securing a witness, arrest warrant, extradition and seizure, personal and house search.