This study addresses the topic of constitutional criminal guarantees in criminal trials, within a comparative study framework with Egyptian legislation, highlighting the position of comparative judiciary, especially the Supreme Constitutional Court of Egypt and the European Court of Human Rights, within the limits necessary for judicial comparisons. The importance of this study lies in shedding light on the guarantees that the legislator must consider when achieving all the regulations related to criminal trials at the trial stage. The research problem of this study is to determine the adequacy of constitutional criminal guarantees during the trial stage in Omani legislation compared to the principles established by the European Court of Human Rights. It aims to analyse the nature of the guarantees that the accused enjoys during the criminal trial stage, and to determine whether the Penal Code, the Code of Criminal Procedure, and complementary criminal laws have fulfilled the legal guarantees for criminal trials as stipulated in the Basic Law of the State, which ensure the rights and freedoms of individuals, thus ensuring a legal trial for the parties involved in the public lawsuit. This study is divided into a preliminary chapter to define the nature of criminal trials, and two main chapters. The first chapter deals with the legal guarantees related to the court, including an explanation of the principles related to the court at the trial stage such as the principle of judicial independence, the principle of equality before the law and the judiciary, and the principle of the publicity of criminal trial procedures. The second chapter is dedicated to discussing the guarantees related to the accused, identifying the most important ones, namely: the presumption of the accused's innocence and the right to defence. The researcher adopted the descriptive-analytical method and the comparative method in this study.