Background: Knowledge brokering plays an important role in the evidence-to-policy system, but little is known about whether and how it occurs within government departments. Aims and objectives: Using empirical evidence from one UK government department, this article analyses how knowledge brokering takes place inside the policy making process and what shapes brokering activities. Methods: Between 2019 and 2021, 25 semi-structured interviews were conducted with current and former senior officials at the UK's Department for Environment, Food and Rural Affairs (Defra). We combined existing knowledge brokering frameworks to investigate the daily activities of a group of officials known internally as 'evidence specialists'. Findings: Defra's evidence specialists routinely performed a range of activities to improve the uptake and use of evidence by their 'policy maker' colleagues. These conformed well to our knowledge brokering framework and included informing, relational, framing, institutional and some co-production activities. They could act as brokers because of the separation of roles of evidence specialists and policy makers; and their brokering work was shaped by organisational, structural and process factors. Discussion and conclusion: Knowledge brokering can play a key role in improving evidence use inside government departments, though this may vary between jurisdictions because different administrations may vary the roles and functions of groups of civil servants. Understanding how different roles could contribute to a brokering approach to evidence use would help fill a gap in researchers' understanding about the evidence-to-policy process and help government departments formalise and strengthen the ways they acquire and interpret evidence to inform policy decisions.