This study investigated whether curriculum modifications predicted student and teacher behaviors related to the general education curriculum and if there were differences in ecological, student, and teacher variables depending on the presence of such curriculum modifications. The study observed 45 high school students with disabilities during instruction in core content areas. Findings indicated that there were significant differences in student and teacher variables depending on the presence of curriculum modifications. When curriculum modifications were provided, students were engaged in more academic-related responses and fewer competing behaviors and teachers were engaged in fewer classroom management activities. Implications and recommendations from these findings are provided pertaining to the importance and implementation of curriculum modifications for students with disabilities in general education settings.