Policy decisions about the approval and funding of new cancer drugs must often be made in an environment of complex uncertainty about clinical and cost-effectiveness data. The focus of this article is on the results from qualitative interviews with senior officials (n = 16) who make decisions about or influence cancer drug policy in various organizations in the Canadian cancer control system. Most participants identified the use of a limited number of informal approaches to address uncertainty, such as grounding decisions in evidence and advice from expert groups. People tended to focus on evidence informed decisions including price negotiations, the ability to implement policy changes, and stakeholder values. Lessons from the Canadian context related to continuing efforts to build a public culture of understanding into how policy decisions like cancer drug funding are made may result in greater acceptance and increased confidence in health policy decision-making processes across multiple sectors internationally.