A bstract In recent years, the centres of Polish cities were subject to intensive urban regeneration processes. This was due to the availability of European Union funds (since 2004), which made it possible to finance projects curbing the degradation of urban areas. Since 2015 the Polish Urban Regeneration Act has structured the urban renewal programming process and has created new legal tools that facilitate public intervention in the most neglected areas. At the same time, gentrification processes have occurred in m any Polish cities, either in conjunction with or as a result of urban regeneration. While urban regeneration is usually met with a positive response from city inhabitants, gentrification causes conflicts which are difficult to resolve. The aim of this paper is to analyse and assess the social manifestations of urban renewal and gentrification processes in deprived areas using the city of Poznań (Poland) as an example. Activities initiated by Poznań's local authorities are considered to be exemplary in Poland and as a result, they are imitated by numerous other cities. The paper presents the results of an analysis of changes that took place in the years 2006-2019 in the city centre that developed a municipal regeneration program. The transformations identified include an increase in property prices and rents and above all, a dramatic transformation of the social structure. The spatial consequences of these changes include the improved condition of residential and public buildings, restoration of green areas and modernisation of other public spaces. The paper attempts to assess which of the two processes, urban regeneration or gentrification, is the principal driving force behind the changes mentioned above.