The Constitution of India directs the State to enforce fundamental rights of the citizens as well as preserve public order, peace and tranquility across the nation. Precisely, the idea of maintenance of the ‘public order’ & ‘freedom of a democratic society’ demonstrates a rational justification for the existence of preventive detention. Article-22 of the Constitution gives detention power to the State for the protection of nation security and maintenance of international friendly relations, tranquility & peace of the entire society from antisocial and subversive elements namely antinational or smuggling activities or persons engaged in illicit trafficking of narcotic drugs and psychotropic substances, etc. The supreme goal is to prevent the perpetrator from causing mischief through his or her dangerous designs and radical ideologies however, the judiciary has showed its concern towards the irrational application of such laws and classified it as a most unwholesome encroachment upon the liberties of the people. Since the entire fabric of the Constitution revolves around the Constitutionalism and the Rule of law which implies a constitutional obligation of the State to enforce its provision in letter and spirits primarily the notion ‘procedure established by law’ in Article-21 of the Constitution which works as guiding factor for the authorities wherein the concept of ‘due process of law’ lies in its spirit. The judiciary has adopted the notion ‘procedure established by law’ in the guise of what ‘it is’ including ‘it ought to be’. The author analyses the concept of preventive detention with the help of two notion namely ‘procedure established by law’ & ‘due process of law’ in the light of judicial pronouncements.