The COVID-19 pandemic has been a major turning point in scholarly attention to information-related problems, including the infodemic and fake news. The paper presents a systematic and comprehensive literature review on multidisciplinary research into problematic information around COVID-19 published in 2020, with a view to identifying the main trends from a disciplinary, methodological, and substantive perspective. We collected 862 records in English from three leading scientific databases (Scopus, Web of Science, and EBSCOhost) by searching, in the title and abstract, a set of keywords related to COVID-19 and information problems. After removing the duplicates and documents other than scientific papers published in scientific journals (such as magazine articles and letters), the three authors screened the records to retain the empirical articles which dealt more than just incidentally with the topic, ending up with 378 papers. The three coders analyzed the results and applied a number of pre-defined categories related to the disciplinary, methodological, and substantive characteristics of the papers. Analysis of frequencies and computational methods, including social network analysis and text mining, were used to analyze the data. The corpus of 378 papers published in 2020 on problematic COVID-19 information revealed considerable contributions from Medicine and Social Sciences and a disciplinarily and geographically interconnected field. Quantitative methods and especially surveys stand out as the most popular approaches, with a considerable number of more discursive papers offering expert views on pandemic-related informational problems. The main trends from a substantive perspective were conspiracy theories and their impact on norm compliance, and the attention to informational problems defined though the concept of infodemic.