The Amazon has a population that is largely urban. However, research is limited regarding representations and analysis of the urban Amazon. This article represents and describes Amazonian urban areas by applying a multicriteria urbanization index. Using the Ecuadorian Amazon as a case study, we constructed this index considering spatial indicators of fractal dimension, number of paved streets, urban luminosity, population density, and Euclidean distances from each urban patch to the closest deforested area, to the closest oil pollution point, and to the closest mining pollution point. The multicriteria urbanization index was classified in five classes (degrees) of urbanization: very low, low, medium, high, and very high levels of urbanization. Most of the urban areas have a low degree of urbanization; notwithstanding, there are areas with a medium degree of urbanization encompassing consolidated cities and suburbs, with a high potential for extension in the future. There are also areas of high and very high urbanization related to the oil industry, including cities which have a high impact on the territorial system of the Amazon. This investigation serves as an introduction to multidimensional spatial and quantitative analyses of the urban Amazon. We suggest monitoring the urban advance in the Amazon using the index developed in this investigation, to support better territorial planning in this region of the world having high strategical importance.