A major obstacle to cross-country research on the role of revenue and taxation in development has been the weakness of available data. This paper presents a new Government Revenue Dataset (GRD), developed through the International Centre for Tax and Development (ICTD). The dataset meticulously combines data from several major international databases, as well as drawing on data compiled from all available International Monetary Fund (IMF) Article IV reports. It achieves marked improvements in data coverage and accuracy, including a standardised approach to revenue from natural resources, and holds the promise of significant improvement in the credibility and robustness of research in this area. This paper sets out the issues with existing sources and explains the process of creating the new dataset, including a discussion of remaining limitations. It then presents data on tax and revenue trends over the past two decades, while a concluding section briefly considers potential strategies for, and barriers to, more effective data collection in future.