This paper deals with a diachronic and comparative study between two Atlantic cities: Salvador da Bahia, Brazil, and Las Palmas de Gran Canaria, Spain, analysing their recent transformation. We study the evolution of both cities in relation to their respective ports and the concordance and differences existing in both processes. The comparative analysis addresses the geography of each city, as well as the origin and development of the port and urban areas. Although with logical differences, both spaces seem to have gone through similar processes of development, although the causes and results differ from case to case.