India practices constitutional democracy with emphasis on constitutionalism. The judiciary protects the Constitution and the rights of the citizens from arbitrary actions of the legislature and Executive for which the judiciary has assumed the onerous role of a watchdog of the Constitution. This paper discusses in detail about the origin and evolution of Judicial Review, and the process of judicial review followed in Germany and Bangladesh and further discusses about the features, types, criticisms and justification of judicial review in India by way of examining various landmark cases and recent decisions pronounced by the Hon’ble Supreme Court and High Court’s. The paper also discusses about the Judicial Activism in Indian perspective. Some believe that judicial activism is necessary for the protection of public interest, others are of the opinion that as a judicial function, courts are required to interpret law and not make them. To observe whether the Supreme Court in such cases has ‘expanded’ its judicial functions beyond its mandate, thus blurring the concept of separation of powers enshrined in the Indian Constitution. To check upon the need for Judicial Restraint. The paper contends that judicial activism has done positive justice but judiciary has to take care of sanctity of the Constitution. For this purpose, various constitutional provisions and judicial decisions are examined.