This article analyzes judicial activism as a result of the denaturation of the typical functions of the Executive and Legislative, added to the crisis of legitimacy, representativeness and functionality that breaks the balance of powers. In order to do so, the qualitative bibliographical method is used, applied to the Brazilian Constitution, doctrine and Brazilian legislation to question the abusive use of the Judiciary's jurisdictional control, reflected by the activist posture, which is in dissonance to judicial control in times of democratic instability. In this sense, the configuration of judicial activism in the Brazilian judicial system is explored, emphasizing the decisions of the Supreme Court and considering the relations and interventions in the performance of the Legislature, as in the case of party (in)fidelity and the relativization of the notion of res judicata in tax matters. Moreover, a comparison is sought between the scenario faced and what the legal system provides as procedure, a fundamental instrument for the consolidation of legal security as an inseparable pillar of the Democratic State of Law. Finally, it is ascertained the possibility of accepting judicial activism in an exceptional character and contrast it with judicial control, whose asymmetry with activism is often disregarded, since they are dissimilar conducts.