Background: Despite the known need for empirical research-to-policy studies, little is known about the factors and conditions needed to support meaningful evidence use or how to intervene to promote quality evidence use. Aims and objectives: To study research-policy processes empirically and descriptively, we conducted an ethnography that focused on the impact of the Research-to-Policy Collaboration (RPC) on legislator and researcher evidence use or policy engagement, including whether and how researchers and policymakers created and sustained meaningful relationships. Methods: The ethnography included participant observation as well as pre- and post- semi-structured interviews from policymakers (n=17), researchers (n=23), and RPC staff (n=5). The team attended relevant events as well as observed the formal and informal ways research is used in policymaking. Findings: In the paper, we describe how 1) legislative priorities were identified; 2) networks were established and maintained; 3) trainings evolved over time; 4) relationships between RPC staff, congressional staff, and researchers were facilitated; and 5) RPC followed up with policymakers and researchers. Discussion and conclusions: We 1) describe the experiences of participants and whether involvement in the intervention changed attitudes or behaviours about evidence use in policy; 2) describe the RPC process in practice, and how it was implemented and evolved over time; and 3) better understand the conditions supporting evidence use in policymaking. We conclude with the value of the RPC as a resource to fill a niche within the evidence and policy space, as well as suggestions for future research-to-policy programmes and practices.