The research problem concerns the methods of modernisation of the market squares of small and medium-sized towns in Poland in the context of contemporary climatic and environmental challenges. The revitalization processes of downtown districts, carried out in Poland since the 1990s, focus on improving living conditions and the quality of space, but they do not take into account the need to adapt to climate change, and even deepen the negative effects of climate extremes (storms, heat waves and urban heat island). The key role is played by conservation guidelines aimed at restoring the functions of the squares in their historical form, devoid of greenery, which does not meet the modern adaptation needs. Examples of old market modernisation in 16 small and medium-sized Polish towns in the period 2005-2021 were analyzed in order to examine the objectives of transformations and their effects in the field of greenery and water management. Based on a detailed analysis of the revitalization programs and the guidelines contained in the Terms of Reference (ToR), it has been proven that rigid requirements limiting the possibility of implementing blue-green infrastructure supporting adaptation to climate change are defined at the very beginning of investment planning. The study proves that changes in terms of greenery most often include the removal of trees in favor of uniform, paved square surfaces. None of the examined projects provided for the possibility of surface rainwater retention, and only in 1 an underground retention system was used. The growing environmental and climate awareness of the society leads to the residents' opposition to greenery degradation projects. Social dissatisfaction is also the reason for modifying projects, but the principles of social participation are not commonly applied and optimally used.