The paper deals with the matter on the parties to criminal proceedings. Parties as procedural subjects that have opposite functions but equal rights in criminal proceedings. The main division of the parties is into plaintiff and defendant. The prosecutor conducting the criminal prosecution has been elaborated in particular with regard to his main division, ie the public prosecutor, the private prosecutor and the subsidiary prosecutor. The position of each special prosecutor in the proceedings and their main functions are explained. The defendant is described as the person against whom the proceedings are being conducted, emphasizing his rights and the defense performed by the defense counsel. The case law shows that abuse of the rights of the parties in the proceedings is a frequent case. The matter of abuses is divided into abuses for each specific party with an emphasis on repressive and preventive regulations aimed at combating abuses of the parties and all abuses in the legislation in general.