Introduction: Evidence-based practice is a process through which evidence in its various forms is sourced, appraised and applied in order to solve a problem, inform decision making, or improve practice. The purpose of this paper is to share findings from a qualitative research study that sought to identify evidence used by Australian special librarians, and explore influences associated with its use. Method: Data was collected through participant diaries and semi-structured interviews with five special librarians to capture and explore evidence use in practice. Analysis: Participant diaries were used to inform semi-structured interview questions. Data from the interviews was analysed using the constant comparative method to determine common themes. Results: Findings describe the role of evidence from a practitioner's perspective, which included what constitutes evidence in practice, and how and why it is used. This led to the development of a "map" of evidence used by Australian special librarians, guided by existing evidence-based practice frameworks. Conclusions: Results raise awareness of the types and uses of evidence in different circumstances by special librarians. Findings contribute an initial understanding of what constitutes best available evidence in the current evidence-based library and information practice model in the context of special libraries.