This article introduces the European Union Policy - Making (EUPOL) dataset. The dataset contains the complete records of the European Commission’s PreLex database, which tracks the interactions between the European institutions on legislative proposals and non-legislative policy documents over time. To be of maximum use to the research community, the dataset is both comprehensive and replicable. It relies on 2600 variables to describe the detailed event histories of more than 29,000 inter-institutional decision-making processes between 1975 and 2009. The data collection has been completely automated, enabling scholars to scrutinize and replicate the generation of the dataset. To illustrate the dataset’s general utility and discuss specific pitfalls, I present a descriptive analysis of the outcome and duration of Council decision-making.