Aim. The presented study aims to develop the methodology for assessing the quality of management of organizational transformation processes. Tasks. To achieve the set aim, the authors solve the following problems: determine the essence and content of socio-economic transformation, formulate quality assurance principles for the management of transformation processes, draw attention to the problem of selecting a unified quality criterion for the management of organizational transformation processes. Methods. This study uses general scientific methods of cognition, including analysis and synthesis. It also applies a systems approach to identify the major problems of assessing the quality of management of transformation processes, including the problem of selecting a unified quality criterion for the management of transformation processes and formulating the principles of ensuring the quality of management of transformation processes. Results. The global problem of managing transformation processes in the economic system consists in the complexity of the managed processes, which increases due to the multidimensionality, mutual influence, and the resulting uncertainty of interactions between the elements of the system. It is concluded that the methodology for assessing the quality of management of transformation processes is based on the principle of integrating separate measures to improve the quality of management of system elements into a single system of management actions and the principle of ensuring that management actions are primarily aimed at preventing possible negative consequences of the transformation of economic systems, i.e. reducing the potential impact of unfavorable events and their consequences. To assess the effectiveness of targeted management actions and productive actions aimed at organizing, controlling, and guiding the transformation process, the authors actualize the problem of selecting an adequate quality criterion for the management of transformation processes in economic systems and put forward a hypothesis about a possible unified criterion of management quality. Conclusions. The principle of integrating separate measures to improve the quality of management of system elements and the principle of ensuring that management actions are aimed at preventing possible negative consequences lie at the core of the methodology for assessing the quality of management of transformation processes in economic systems. The quality assessment methodology should be developed in the direction of finding a unified quality criterion for managing transformation processes in economic systems.