In this chapter, we will dissect the salient elements of urban planning in terms of theoretical foundations and methodology, in order to demonstrate that in addition to criticism expressed by a certain number of authors regarding its transfer to cities of the South, urban planning does not focus on the key issues faced by local authorities and inhabitants, both in terms of target population groups and the infrastructures and services that should be given priority. We will highlight the translation of these theories, essentially of western origin, and their application to "other societies", trying to understand how throughout the course of history, this intellectual configuration of the city has been replicated in contexts subject to other injunctions and constraints. We will then deconstruct urban planning, viewing it not as a science but rather as a method that is applied with fieldadapted techniques, based on precepts that often lack clear definition, yet that is guided by instruments that can spatially and materially organize the distribution of individuals, their activities, goods, services, facilities and equipment, within a territory that is identified for geographical and administrative reasons. Urban planning takes into account the potential and the limitations of the natural (spatial and environmental) and human entities in question, including in its analysis the causes and impacts of the dynamics that affect the transformation of the city and its dwellers. The difficulty with urban planning is that it is based more or less explicitly on different disciplines (urbanism, architecture, engineering, economics, sociology, geography, etc.), that function independently with no formal obligation to work together/ cross reference, which means that many professional practices are used periodically and repeatedly. Sustainable development and urban sustainable development represent a conceptual framework allowing us to rethink urban planning. More than a technical tool giving voice to all stakeholders, a participatory approach is the most advanced methodological manner of anchoring planning in a local and regional democratic policy. As broadcast by the United Nations in 1987, "sustainable development" is defined above all by two essential components. First, the time factor, by emphasizing that development can only be sustainable if it "meets the needs of the present without compromising the ability of future generations to meet their own needs".