The port-city relationship is an interesting theme to study in order to better understand the dynamics of capital and land use in port cities, which are considered global cities due to certain characteristics, Sassen (2001). Researches on these relationships show a paradox observed in port areas: a large potential for development associated with a spiral of obsolescence. This work encompassed many stages which allowed for a better understanding of what global cities are and of how port cities attain that status. The development of interoceanic navigation was determinant for these cities to become centers of a cosmopolitan and globalized culture. This study aimed to discuss these questions defining how the port-city relationship takes place in Brazil and worldwide, as well as identifying the socioeconomic, socio-environmental and historical forces that guide the creation, growth and maintenance of modern port cities. This work encompassed many stages which allowed for a better understanding of what global cities are and of how port cities attain that status. The development of interoceanic navigation was determinant for these cities to become centers of a cosmopolitan and globalized culture. This study aimed to discuss these questions defining how the port-city relationship takes place in Brazil and worldwide, as well as identifying the socioeconomic, socio-environmental and historical forces that guide the creation, growth and maintenance of modern port cities.