Literacy in science is important for all students and is one component of access and progress in the general education curriculum. One barrier to science literacy for students with autism spectrum disorders (ASD) is the extensive amount of vocabulary involved in comprehending science content. Based on the inherent link between vocabulary knowledge and comprehension, graphic organizers (GOs) paired with explicit instruction can improve vocabulary as well as comprehension for students with disabilities. Using a multiple probe design, three students with ASD and intellectual disability were taught various scientific concepts related to convection (e.g., precipitation, condensation) via systematic instruction that included constant time delay and multiple exemplars of a teacher-directed GO. A functional relation was demonstrated between the GO with systematic instruction and students' number of correct steps completed on the task analysis. Future research and implications for practice are discussed. (Contains 2 tables and 3 figures.)