The Parliament and Government Composition Database (ParlGov) is a new type of data infrastructure that overcomes the shortcomings of many contemporary approaches towards data collection on political institutions. With ParlGov, we aim to provide an infrastructure that systematically combines information on party positions, election results and government composition. ParlGov offers: a database and data tables for the empirical study of parties, elections and governments; a web interface with a comprehensive and accessible way of presenting the coded information, and feedback mechanisms to continuously improve the data collected over time. Currently, ParlGov contains data on elections and governments for all EU and most OECD members for the entire post-war period. The database combines approximately 1400 parties, 640 elections with 5500 election results and 2100 governing parties in 890 cabinets. This information is linked to various external data sources. Releases at regular intervals will provide up-to-date empirical information including recent elections or changes in government, coding suggestions from country experts as well as extensions to more countries and time periods.