The sources, types, and mechanisms of formation and tools for minimizing "unintended consequences" of economic reforms in Ukraine are considered. "Unintended consequences" are understood as unpredictable, unintentional, indirect, and incredible consequences of actions of initiators, organizers and executors of Ukrainian reforms, which were not included in their plans but happened in reality and have have a decisive influence on the state of the national economy. The methodological basis of the study includes historical-genetic, comparative, statistical, and graphical analysis. The origins of the study of " unintended consequences" of human actions can be traced in the works of N. Machiavelli, J. B. Vico, B. Mandeville, A. Ferguson, W. Petty, A. Smith, J.-B. Sаy, K. Marx, С. Menger , W. Pareto, M. Weber, F. Hayek, and R. Merton. Prerequisites for the "unintended consequences" of economic reforms in Ukraine include insufficient competence of initiators and organizers, errors in analyzing problems due to ignoring the specifics of the current situation, focus on achieving immediate results without the possibility to calculate long-term consequences of implemented measures, underestimation of the role of basic values of national culture and the impact of disclosure of predictions on the behavior of economic entities. The types of “unintended consequences” that affected the course of economic reforms in Ukraine include those that, while remaining functional for the system, rely on latent, unconscious and unplanned factors arising from latent dysfunctions. Varieties of mechanisms for the formation of "unintended consequences" of economic reforms in Ukraine include the manifestation of the results of latent functions, self-realization of social beliefs and self-destructive beliefs. It is substantiated that the practice of mandatory preliminary testing at the local level on the basis of relevant information platforms makes it possible to eliminate shortcomings in advance, clarify and improve the implemented measures, determine their social effectiveness, and choose the best alternative. Conducting preliminary economic experiments avoids situations where, as a result of the reform, certain groups gain access to various types of rental income at the expense of society.