The chapter examines grassroots artistic practices as transformative forces in contemporary urban contexts, focusing on their ability to propose alternative practices of cultural and social engagement and urban management. Specifically, it explores how grassroots artistic practices, especially artist-run spaces, reinvent the logic of the art market through practices of dissent. The research analyses the case of Associazione Bastione, an independent art space in Turin, Italy, which emerged as a grassroots artistic practice through the reappropriation of a neglected historic building in the city centre. Despite the local specificity of the case, the thematic analysis of semi-structured interviews with members of Bastione identifies coherent themes: (1) Art in urban spaces: using reclaimed spaces for artistic experimentation; (2) Promoting urban regeneration through the artistic regeneration of heritage and community development; (3) Reinventing alternatives to the lack of response from local government. Ultimately, the findings highlight how grassroots artistic practices resist processes of gentrification while fostering the creation of cultural ecosystems and urban communities. However, they also reveal the need for more flexible governance models to support these practices and ensure their transformative potential.