This paper examines the impact of the implementation of participatory budget (PB) projects on the development and creation of public spaces in the city. The first part of the paper describes the main assumptions and models of participatory budgeting as well as the legal basis and rules of PB implementation and financing in Poland. In the second part, those are confronted with the implementation of PB (civic and green) in Lublin in 2015-2019. In the third one, detailed analysis of the PB rounds 2015-2017 show that 86% of investment projects submitted and 87% of projects selected for implementation were directly associated with activities in public space. Furthermore, the spatial distribution and thematic scope of those investments in 27 districts of Lublin in relation to 10 categories selected by the authors as well as the motivation and activity of residents of individual districts in applying for projects were presented. The fourth part shows the changes in Lublin’s public spaces caused by the implementation of PB projects and Lublin’s experience in relation to other cities in Poland. The summary includes recommendations on how to effectively implement BP to create a high quality public space in cities. Three aspects are distinguished: 1) organizational and procedural; 2) mobilisation of the stakeholders and 3) implementation of projects.