In recent years, with the development of society, the awareness of environmental protection for people has been increasing. While ports promote the economic development and employment levels of port cities, they also have a negative impact on the environment of port cities. The sustainability of port cities is increasingly valued. Port cities face huge challenges, and their sustainability needs to be better understood. The purpose of this article is to review research on the sustainability of port cities. We used content analysis to classify and analyze the existing relevant literature, to learn about the hotspots and deficiencies of past research, and to propose future research directions. We found that port sustainability has become an increasingly important research topic during the past ten years. From the perspective of geographic research areas, European port cities are the hot spots for sustainability research. Regarding research fields, technologies, methods and measures to promote the sustainability of port cities are popular research topics. In terms of research methods, qualitative research plays an important role in the study of port city sustainability. Finally, guidance for future research on port city sustainability is proposed according to the review results.