Historically, ports have been an important location factor for cities, enabling international trade and investment and facilitating urbanization processes. However, the traditionally strong relationship between ports and port cities has gradually weakened due to the emerging negative externalities of ports. Therefore, port-city municipalities need to better understand the relationship between port activities, urban competitiveness, and the attraction of investment. This paper uses the Quadratic Assignment Procedure (QAP) and related regression models to test this relationship as well as identify the determinants of urban competitiveness. The results show that despite the positive relationship between port and urban networks, port cities currently exhibit no significant advantages over non-port cities in attracting Foreign Direct Investment (FDI); in addition, port-city competitiveness depends more on urban characteristics than on port factors. Based on these results, we propose various strategies for port-city developments.