Tianguis shaping ciudad. Informal street vending as a decisive element for economy, society and culture in Mexico. Silvia Mete 1 Luca Tomaino 2 Giovanni Vecchio 3 The paper aims at showing culture as a feature capable of shaping urban environments, both promoting specific phenomena and making a stand to transformation attempts. Tianguis, the informal Mexican markets, appear as a demonstration of this shaping ability, being relevant not only for informal economy, but also for urban settings and social networks created by their presence. On the other hand, the phenomenon of Walmart spreading – now diffused in many growing countries (e.g. Brazil, China, India) – is opposing a totally different model of commerce and even lifestyle that tries to tame traditional forms of trade replacing them in their usual settings. Such a relevance is also proved by the attitude of institutions, which are unable to face the problems set in the political agenda but also passive when receiving proposals from external actors. Keywords: Informal street vending, Social capital, Culture of poverty 1 School of Architecture and Society, Politecnico di Milano. E-mail: silvia.mete@gmail.com 2 School of Architecture and Society, Politecnico di Milano. E-mail: lucatom89@gmai.com 3 School of Architecture and Society, Politecnico di Milano. E-mail: giov.vecchio@gmail.com