There is a growing emphasis on meeting the diverse educational needs of all students which has drawn attention towards inclusive education. The number of students with severe disabilities receiving instruction in inclusive education settings has steadily increased over the past decade (U.S. Department of Education, 2004). Limited research has been conducted on the acquisition of grade-aligned science skills for students with severe disabilities (Browder et al., in press; Courtade et al., in press, Jimenez et al., in press), and even more limited on academic skills in inclusive settings (Carter et al., 2007; Dugan et al., 1995; Jameson et al., 2009). The current study examined the effects of peer-mediated time delay instruction to teach science responses and KWHL chart responses during inclusive inquiry science lessons to students with severe intellectual disabilities. Six general education peers were trained to implement an embedded constant time delay procedure during three science units with five students with severe disabilities. Results indicated that all five students increased the number of correct science responses during all three science units. In addition, all six peers were able to implement the intervention with high fidelity. Finally, high levels of social validity were reported by peers, as well as the general and special education teachers.