This article describes the ifo Prussian Economic History Database (iPEHD), a public use county-level database covering a rich collection of variables for nineteenth-century Prussia. The Royal Prussian Statistical Office collected these data in several censuses over the years 1816-1901. These data provide a unique source for micro-regional empirical research in economic history, enabling analyses of education, religion, fertility, industrialization, and many others. The service of iPEHD is to provide the data in a digitized and structured way.