Evidence-informed policy-making is seen by many as crucial for formulating effective solutions to the complex challenges facing societies today. However, scholarship on evidence and policy-making has repeatedly noted that the use of evidence in government policy-making is highly uneven across policy areas and organizations. Still, we have surprisingly little systematic empirical knowledge about how government organizations actually differ in the use of evidence in policy formulation, and we lack a solid understanding of what accounts for differences across organizations in evidence use. The article seeks to address these knowledge gaps through an analysis of ministerial evidence cultures. Arguing that the government bureaucracy is not a unified entity but rather a collection of organizations with distinct world views and ways of doing things, we expect to find distinct evidence cultures in different government ministries. Moreover, we contend that the informal norms and practices of evidence use leave empirically traceable marks that can be examined quantitatively across ministries. The article maps evidence cultures across all Norwegian government ministries in the period 2000–2020 based on data on ministries’ commissioning of research reports, appointment of experts to advisory commissions, and references to knowledge sources in white papers, revealing striking and systematic differences in evidence cultures across ministries. It also empirically investigates how different evidence cultures are related to institutional differences in task environment, analytical capacity, and personnel. The article contributes both to literature on evidence and policy-making and to public administration scholarship.