This paper is part of the results of an investigation passage on the subjects of the urban environment and their implications in the urban planning and development of intermediate cities in Colombia.The investigation inspires reflections around the viability to recognize or not the city as an ecosystem within an urban-environmental context; first of all, the text will clarify concepts on the Colombian intermediate city; second, it will define which is the atmosphere of the city; third it will establish concepts on the option of recognizing the city as an ecosystem thus to mitigate the dynamic process of a great environmental problematic an one caused by the slumses; and finally, some conclusions will be exposed that will pretend to affect future decision making in order to plan the territory from an ecosystemic vision.