The topic of this paper is pre-trial detention. Pre-trial detention is regulated by the 2008 Criminal Procedure Code. Prior to the enactment of the current Criminal Procedure Code, the institute of pre-trial detention was regulated by the 1997 Criminal Procedure Code. The paper will analyze the amendments of the older Criminal Procedure Code from 1997 that are related with pre-trial detention and also current legal provisions that regulate pre-trial detention under the Criminal Procedure Code from 2008, and its amendments. The central part of the paper focuses on the substantive and formal legal preconditions of pre-trial detention, the notion of reasonable suspicion, grounds for pre-trial detention, jurisdiction, duration of pre-trial detention, hearing, abolition and revocation of pre-trial detention and control of pre-trial detention. The fourth chapter analyzes the European Convention on Human Rights. The last part of the paper refers to the judgment of the European Court of Human Rights (the court established by the said Convention). The paper analyzes some verdicts against the Republic of Croatia concerning pre-trial detention and violation of Art. 5. from the Convention, as follows: Šebalj v. Croatia, Trifković v. Croatia, Čutura v. Croatia, Bernobić v. Croatia, Perica Oreb v. Croatia