This article addresses the question of whether the European Central Bank’s (ECB’s) involvement in banking supervision is compatible with its independent status as provided by the European Union’s (EU’s) primary law, specifically with reference to the principle of separation between the ECB’s monetary policy and supervisory powers. It is found that the Single Supervisory Mechanism (SSM) Regulation provides the ECB with a set of prerequisites in pursuit of its supervisory objectives under a high level of independence. However, the article argues that the current EU regulatory framework poses risks to the overall independence of the ECB. In particular, the principle of separation, as one of the mechanisms aimed at safeguarding the ECB’s independence, is not fully achieved. In addition, the boundaries and application of macro-prudential operation of the ECB in both the SSM and European Systemic Risk Board (ESRB) remain blurry and uncertain. The article concludes by suggesting that the only way to safeguard the independence of the ECB is by carefully revising the ECB’s competencies, which may require treaty amendment.