Urban Agriculture can enable possibilities to combat structural inequalities in contexts of social vulnerability, providing: income generation; improvements in the quality of life of urban farmers; expansion in the production and access of food suitable for human consumption; and environmental preservation. In this direction, this presentation shows part of the results of research conducted in a socially vulnerable area of São Paulo, Brazil and Lisbon, Portugal. The findings for São Paulo are: (a) the growing female protagonism in agroecological urban agriculture, associated with popular entrepreneurship and the awareness of the injustices that female urban farmers face; (b) the disputes among community garden´s management models and cultivation concepts; (c) informality in access to land for urban agriculture and no guarantees of permanence in the community gardens' lands. The findings for Lisbon are: (a) Urban Agriculture is highly regulatory, materialized in the Horticultural Parks project conducted by Lisbon´s City Council; (b) untapped potential for mobilization and popular participation of urban farmers in social districts; (c) untapped potential for social-environmental innovation in initiatives led by the youth. The study concludes that the AU activity, in the studied contexts, causes a wide improvement in the quality of life of urban farmers; initiates or expands local production of food suitable for human consumption by vulnerable populations; urban agriculture practices are associated with environmental preservation and the promotion of environmental awareness through pedagogical practices. In short, urban agriculture – materialized in activities of an emancipatory, assistance or regulatory nature – has the potential to combat structural inequalities faced by vulnerable populations, contributing to social and economic transformations in large cities.