Federal mandates as well as the National Science Education Standards call for science education for all students. IDEA (2004) and NCLB (2002) require access to and assessment of the general curriculum, including science. Although some research exists on teaching academics to students with significant disabilities, the research on teaching science is especially limited. The purpose of this investigation was to determine if teachers of students with moderate and severe intellectual disabilities could learn to use a task analysis for inquiry-based science instruction and if this training increased student responding. The findings of this study demonstrated a functional relationship between the inquiry-based science instruction training and teacher's ability to instruct students with moderate and severe disabilities in science. (Contains 4 tables and 3 figures.)