The purpose of this study was to examine teacher perspectives about evidence-based practices (EBP) and decision-making for students with intellectual and developmental disabilities. Given the current EBP movement, our study sought to understand practitioner definitions and perspectives on EBP and decision-making. Interview data from nine special education teachers who work with students with intellectual and developmental disabilities were conducted, and then transcribed and coded in order to examine their perspectives and beliefs about how organizations, people and tools influence their understandings of EBP. Findings demonstrated that how teachers conceptualized EBPs and described their decision making about instruction was complex and painted a multi-faceted image of how they conceptualized organizational constraints, considered the value of research, and what tools were available to them.