Human activities lead to several impacts on marine ecosystems, among which a massive input of plastic entering the marine environment. This scenario has the potential to threaten ecosystem health and integrity, also reducing the ability of marine ecosystems to provide good and services on which human well-being relies. In this study, the global scientific literature on marine microplastics was explored by combining social network analysis and bibliometrics. Network maps displayed the relationships among keywords, authors, countries, and journals dealing with the issue of microplastics in marine ecosystems. The citation analysis of journals showed that “Marine Pollution Bulletin” resulted the first among the scientific journals publishing articles on this subject. The results also highlighted that most research on the subject is focused on toxicology and environmental chemistry, while ecological studies focusing on the impact of microplastics at ecosystem level are still limited.