Problematic use of the Internet (PUI) generally refers to use of different types of Internet content which is not under control and leads to difficulties in everyday functioning. It involves generalised PUI but also specific forms such as problematic use of videogames, social media, and pornography. The main aim of this paper is to offer a basic review of current trends in defining, measurement and research of PUI. The review of available papers points at methodological problems related to determining the prevalence of PUI, and insufficient direct investigation of postulates of existing models regarding the onset and maintenance of PUI. Moreover, this paper offers a critical review of existing instruments for measuring PUI and its specific forms, and recommends the most appropriate instruments. A short review of PUI research methodology and important findings is given. Finally, guidelines for future research in this area are provided, which enable us to investigate these phenomena of contemporary society in a comprehensive and sound way.