Physiotherapists are generally positive to evidence-based practice (EBP) and the use of research in clinical practice, yet many still base clinical decisions on knowledge obtained during their initial education and/or personal experience. Our aim was to explore motivations behind physiotherapists' use of research in clinical practice. Self-Determination Theory was applied to identify the different types of motivation for use of research. This theory posits that all behaviours lie along a continuum of relative autonomy, reflecting the extent to which a person endorses their actions. Eleven focus group interviews were conducted, involving 45 physiotherapists in various settings in Sweden. Data were analysed using qualitative content analysis and the findings compared with Self-Determination Theory using a deductive approach. Motivations underlying physiotherapists use of research in clinical practice were identified. Most physiotherapists expressed autonomous forms of motivation for research use, but some exhibited more controlled motivation. Several implications about how more evidence-based physiotherapy can be achieved are discussed, including the potential to tailor educational programs on EBP to better account for differences in motivation among participants, using autonomously motivated physiotherapists as change agents and creating favourable conditions to encourage autonomous motivation by way of feelings of competence, autonomy and a sense of relatedness.