Use of empirically unsupported practices is a challenge in the field of autism spectrum disorder (ASD). We explored whether attitudes and perceived evidence were linked to intended practice use in early intervention staff. Seventy-one participants completed ratings of the evidence base, current and future use of six ASD intervention practices, and reported attitudes to research and evidence-based practice. Participants reported greater use and rated the evidence base higher for the empirically supported practices. However, variability in accuracy of evidence base ratings was observed across individuals. Higher perceived evidence was linked to greater future use intentions for empirically supported and unsupported practices. The need for accurate information across practice types is highlighted. Self-report methodology limitations and future research directions are discussed.