This research is under the title of " The Guarantees and Rights of the Accused at the Stage of Investigation in the Saudi System ". The researcher has chosen this subject among the penal subjects of his major due to its importance of being connected with rules and regulations, usually enacted by law involving the procedures of arrest, inspection and detention, when the state - as a general ... [Show full abstract] authority - carries out its duty, as in any legal systems of the world, to combat crime and criminal and to protect the society from his vice. The problem which the researcher seeks to remedy is the extent of equilibrium between the guarantees of rights and interest of the accused individual and the rights and interest of the state in securing and stabilizing its society against crime. Do the procedures of the currently carried out system secure the rights of the accused at the stage of Investigation such as (arrest after suspicion then inspection, apprehension, detention and Investigation) then bring charge against him and bring him to justice, or release him and drop all the charges against him by virtue of the intrinsic innocence of the accused? The research aims to affirm that the systems of Saudi Arabia secure the entire rights of the accused in conformity with Islamic Law. Due to the nature of the research, researcher has adopted the inductive method through scrutinizing the clauses of the governance. constitution, the system of procedures, and the system of imprisonment and detention, as well as the analytical method for those clauses in order to realize the objectives of the research and solve its problem. The structure of the research is divided into three topics. The first is under the title of: The concept of guarantees, rights, the accused and Investigation. The second is under title of: The Guarantees and rights of the accused and their types. The third is under the title of: The Guarantees and rights of the accused in the governance constitution and the penal system procedures. At conclusion, the research reached results and recommendations, the most important of them are: Accused arrest is requirements of detention rather than detention is requirements of arrest. There are guarantees for accused rights at the stage of Investigation secured in conformity with the Islamic Law, governance constitution and the conventional systems and rules in Saudi Arabia. Arrest, inspection, detention, apprehension, and detention are prime elements of penal procedures at the stage of Investigation. Guarantees are considered presumption of innocence of any accused of charges imputed to him by securing his right (as an individual) of defending himself which may render the perpetrator fall into the hands of the state. The research recommends that: to give attention to propagate the culture of being familiar with human rights in penal procedures and increase awareness of it among media workers as well as the public.