The study deals with the significant role of judicial activism in different eras in Pakistan. It examines the role of judicial institutions in damaging the democratic culture of the country. Since the independence of Pakistan, frequent military interventions were validated by the Superior Judiciary of Pakistan. The study discussed these landmark cases which dented the doctrine of Separation of Power in the county. The concept of judicial review has been originated and developed in Britain, and later reached the US in Marbury v. Madison. The history of Pakistan is marred by several instances of Judicial Activism, in which the jurisdiction of the judiciary encroached upon the domain of legislature and executive. In this study, the activism of populist Judges, Justice Iftikhar Chaurdhry and Justice Saqib Nisar has been compared. Their Judicial actions have been discussed in which the domain of the executive has been compromised. The populist actions of Judges dent the independence of the Judiciary and lead to judicial impartiality, as in several cases, different verdicts are observed in the same nature cases. The study concluded by establishing the link between Judicial activism and Separation of powers, as all organs of the states have constitutional limits to work within, The researchers also proposed some judicial reforms, that will maintain the sanctity of the Doctrine of Separation of Power while exercising Judicial Activism.