The purpose of this study was to examine the impact of inclusive versus traditional science classrooms on eighth-grade students' attitudes towards science through mixed research design. A total of 121 students from four eighth-grade science classes participated in this study. The experimental group of students (N=61) learned a unit of structure of matter in inclusive science classrooms in which theory of multiple intelligences (MI) was used as a mediator, aligned with the principles of Universal Design for Learning, to differentiate instructional strategies, assessment approaches and types of assignments, incorporating all students' strengths or intellectual profiles, while the control group of students (N=60) learned the same unit in traditional science classrooms. Changes in students' attitudes towards science over the time period (pre-test, post-test, and follow-up) were assessed using a Likert-scale questionnaire and individual interviews. The results of statistical analysis indicated that compared to traditional classroom, inclusive classroom using MI-inspired lessons significantly improved and maintained the students' attitudes towards science. The quantitative results were further supported by evidence from qualitative data gathered through post and follow-up interviews. This study has implications for the nature of inclusive practices in science classrooms concerning the value of students' attitudes towards science.