The article discusses the legal solutions regarding the polvgraph examinations in criminal proceedings (starting with the detection/location of criminal offender, locating witnesses, collection of ali sort of evidence to be accepted by the court, collection of phvsical evidence which could help to establish the facts, criminal investigation and the elimination of the innocent suspects) with reference to the Criminal Procedure Act (Amendments from 2002) and the Police Act (2000). Pursuant to the provisions of Article 186, item 2 of the Criminal Procedure Act the polvgraph examination is a separate activitv within the police proceedings which differs from the activitv called information gathering. The Article 46 of the Police Act allows for the polvgraph examinations of persons outside the criminal investigation in cases of reported missing persons, suspicious death and the like. The paper introduces the distinction between the adequacy and sufficiencv of the legal regulation of polvgraph examinations as criminal investigation activitv which would guarantee the correct usage of polvgraph during preliminarv investigation proceedings, after it has been explained and accepted that the polvgraph examinations can be used by the police as an efficacious supportive device in criminal investigation. For that reason, the paper doesn't discuss the issue of polygraph examination results as formal evidence in criminal proceedings, which is neither foreseen nor allowed by the Croatian criminal law. It discusses the legal solutions regarding the possibilities of the use of this very effective technic in detecting, investigating and information gathering about the offender and/or the offence, in search for clues and objects which could produce legally relevant facts. The issue, which is important for the future (de lege ferenda), is the usability of polygraph examinations for so-called diagnostic purposes like the testing of specific skills of the examinees or defining certain decisive factors in čaše of a parole release. One of the basic issues of the legal solution of the problem is the protection of human rights and liberties especially from the point of view of person's free will and voluntariness during preliminary criminal procedure.