The metaverse is the next evolution of the Internet, merging the physical and digital worlds into a multiuser environment. It is discussed widely in the media and among technology developers. It may expand to many aspects of society and people’s everyday lives. In this article, we examine how academic discussion and research about the metaverse developed from the 1990s to the end of 2022. We focus on the quantitative development of scientific publications about the metaverse, the key countries and organizations behind these publications, the key research topics and areas, and whether and how those publications addressed sustainability. We identified 491 international scientific publications (peer reviewed articles, reviews, and proceedings papers) related to the metaverse in the Web of Science database and 2240 scientific publications in the Scopus database, between 1995 and 2022. The number of publications is rising very fast as most of publications on the metaverse were published in 2022. Scholars in universities and research institutes in the United States, China, the United Kingdom, and South Korea are the most frequent publishers. Publications very seldomly address sustainability as the main subject. Usually, sustainability is considered very narrowly, despite the metaverse’s large and significant expected future economic and social impact. Sustainability and responsibility should be integrated into the design, construction, and development of the metaverse and related research.