Polycentricity has a broad and complex meaning that varies depending on the spatial, social, economic and historical perspective of the research. In Brazilian context, the metropolitan agglomerations have a predominantly monocentric configuration, which are nowadays experiencing the deconcentration of urban activities and an increase in urban mobility due to various economic and social trends. However, this trend toward polycentric development in Brazil is translated in high socio-spatial segregation and dispersed urban structure. This occurs because of the way to deal with the complexity and dynamism of the metropolis, which does not attend the new urban demands, promoting more fragmented rather than more integrated urban systems. This book examines the concept of polycentrism in its broader sense, providing a more comprehensive understanding about the theme in order to narrow the general definition down to the context of Brazilian metropolises. This investigation takes into account three aspects of the urban system: morphology, socio-economic relationships, and governance, aiming to find out the main synergies (relations) within city.