The publication attempts to comprehend the issues of theory and the role of scientific knowledge, its use in spatial planning of Ukraine. According to the authors, this is extremely relevant for solving spatial planning problems, which are inherently non-deterministic (with many unknowns), complex and related to forecasting the future of the state and territories, and their solution by means of "common sense" alone may be ineffective, and the developed documents may be harmful to the territories and hinder their development. The importance of improving the methodological culture and formation of the urbanist's systemic thinking (level of thinking and reflection, worldview), his creative potential and the set of professional knowledge, skills and abilities to implement projects and other functions of professional activity is emphasised. 
 New changes and new information reveal a systemic perspective as a synergy of urban activities in designing, justifying decisions and managing the development of territorial systems. The creation of new administrative-territorial structures is a chance for Ukraine, in particular for settlements that are depressed due to lack of resources, and a vision of development prospects. In order to take advantage of new opportunities, an effective spatial development policy (based on knowledge as a scientific basis) should be formed and consistently implemented. 
 Spatial decisions determine the prospects of a territory. However, even with correct forecasts and the choice of a spatial development model, it is not enough to establish certain rules. Сritical and systematic thinking by the authorities, the community and professionals is required both in justifying decisions and implementing them. A prerequisite for effective spatial development of territories should be the priority for municipal and state authorities to make spatial decisions. The nature of the new models of territorial development is that they should be implemented by planning, not by national economic plans. This will ensure the transition to a new post-industrial model of development. The article substantiates certain provisions from the experience of territory planning in Poland, which are important and appropriate to use to substantiate the spatial future of Ukraine.