ABSTRACT This paper is an analysis of landmark case of Selvi v. State of Karnataka and deals with important questions pertaining to constitutionality and validity of administration of polygraph tests, brain mapping, and narco-analysis etc.it deals with the reasoning given by the courts for the administration of these tests by the investigating authorities.it also depicts the conflicting position of technology and humanity. The accused are involuntarily administered to these tests which raises lot of question regarding the violation of human rights and fundamental rights. The important legal issues also make a clear stand so as to what all should be done and taken care of while using these techniques. The case gives importance to major legal issues including privacy or personal liberty, self-incrimination and substantive due process and aims to keep the constitutional morality and humanity above all. It also aims to prevent inhuman, degrading and forceful treatment by investigating