This case investigation followed the progress of middle students with disabilities, their peers, and teachers in co-taught science classrooms where a hands-on, inquiry-based curriculum was used. Students with disabilities (n=21), including learning disabilities, mild intellectual impairment, and mild autism were placed in co-taught classes with students without disabilities (n= 41). Science and special educators (n=5) received professional development on implementing co-teaching and inclusive strategies along with time for co-planning and support during the school year. Data collection included pre and posttest administrations of the science subtest of the Iowa Test of Basic Skills (ITBS), classroom observations, and teacher interviews. Analysis of pre and posttest scores on the ITBS indicated significant increases in science achievement for students with and without disabilities. Classroom observations indicated a high level of student-to-student interaction and engagement with teachers and the curriculum and the application of whole-class and individual adaptations to improve learning and behavior. Teachers viewed co-teaching as a valuable method of service delivery for students with disabilities who might otherwise be served in more restrictive settings. Findings were explored in terms of the relationship between co-teaching variables and the curricular and instructional features of the inquiry-based program. (Contains 2 tables.)